Basal body temperature before menstruation. Basal temperature is normal in early pregnancy

Basal chart allows you to monitor the normal course of processes in the female body. Today we will consider the question of what basal body temperature before menstruation and what values are typical for the functioning of the reproductive system on different stages cycle, and especially before the start critical days.

Features of measurements

What you can find out with the basal temperature chart

Any woman, upon reaching puberty, dreams of having an ideal cyclic process, knowing the time of ovulation in order to get pregnant at the scheduled time, or vice versa, to prevent unwanted conception. For this purpose, along with ovulation tests and other methods, temperature measurement in the rectum is widely used. That is why the question of what is the normal basal temperature before menstruation, what should be during the release of the cell and the standards for both phases, is very relevant in the lives of girls. With the help of the graph, you can identify the following points:

whether the follicle is maturing;
day of ovulation;
hormonal disbalance;
day of future menstruation;
the onset of pregnancy.

What is the basal temperature before menstruation (normal)

Before determining what the basal temperature before the monthly norm is in your cycle, we recall that measurements should be carried out for at least 3-4 months for the reliability of the values \u200b\u200bobtained and follow certain rules:

Measurement time 5-7 minutes mercury thermometer or 1 minute - electronic;
Use the same thermometer, shaking it off in the evening;

Do the procedure in the morning, immediately after 6 o'clock restful sleep without getting out of bed and without making sudden movements, preferably at the same time;
Enter the data on a graph, under which to note the slightest deviations in habitual way life (colds, stress, physical overstrain, alcohol consumption, etc.).

Temperature standards at different stages

The study must begin from the first day of menstruation. The values during this period are increased, and therefore are not taken into account. average temperature on the last day of menstruation it will be about 36.3 ° and, fluctuating within the limits of up to 36.5 °, it lasts the entire first phase. This is the most favorable conditions for follicle growth under the influence of estrogen.

On the eve of the release of a mature egg from the ovary, it decreases by several tenths of a degree, and then rises to 37 ° and above, which confirms the fact of ovulation and the beginning of the second phase. Such values are characteristic almost until the end of the cycle.

What basal temperature will be before menstruation depends on the behavior of the egg: fertilization will occur or not. After the breakthrough of the follicle on the wall of the ovary at the site of the wound, corpus luteum that produces the hormone progesterone. He is responsible for fertilization and preparation of the uterus to receive the fetal egg, and increases the temperature to 37.0-37.5 °. These values are the most optimal for the development of pregnancy.

What is the basal temperature before menstruation for a week

A standard chart of temperature values over this period will stably fix these figures. In the case of a successful conception, a similar picture continues before and after the delay, which is the first sign of pregnancy, which will be confirmed by other symptoms and positive result test.

Answering the question, what basal temperature will be fixed before menstruation a week before they begin, the answer is unequivocal: 37 ° and above, but not more than 37.5 °. Although at 28 daily cycle It is at this time that one can see implantation retraction on the graph. It lasts for a day, and a decrease in the thermometer readings is observed by several tenths of a degree. Sometimes it is accompanied by a barely perceptible pain in the lower abdomen and slight bloody discharge from the vagina. They notify future mother about the implantation of the embryo into the wall of the endometrium. However, then the indicators level off and become the same. Moreover, this phenomenon is not observed in all women.

If conception does not happen, the level of progesterone gradually decreases, which leads to a decrease in temperature on the eve of menstruation.

What is the basal temperature before menstruation for 3 days

What will be the basal temperature before menstruation (for 3 days) depends on the individuality of each of the fair sex. Statistics show a decrease of 0.3-0.5°. Values in the range of 36.8-37.1 ° at this very moment are considered standard.

When asked what the basal temperature will be before menstruation (for 3 days), gynecologists answer that the average temperature will be 36.8-37.1 °.

Atypical temperature readings

Exist possible deviations from the norm due to a disease or imbalance of hormones, which is expressed in other indicators on the graph. The most typical examples of deviations are:

progesterone deficiency

Progesterone insufficiency causing downward trend in the graph curve. It is characterized by a slow rise in temperature, which lasts no more than a week. The difference in digital values between the phases becomes less than 0.4 °, the second period of the cycle is shortened to 10 days instead of 14, which causes the appearance of menstruation ahead of time;

endometritis

Endometritis, inflammation of the uterine mucosa, on the contrary, increases the temperature in the first menstrual days up to 37°. Here is the basal temperature before menstruation and on the first day of bleeding calling card this disease. When, after a slight decrease before the start, instead of continuing to fall, there is an increase in indicators, it is clear that one cannot do without going to the doctor;

The basal temperature before menstruation and on the first day, if there is such an inflammatory process as endometritis, is kept at 37 °.

Pregnancy

When pregnancy is confirmed, when the temperature is elevated - up to 37.5 °, menstruation did not start on time, and bleeding from the vagina is noted, indicating a threat of miscarriage. At negative test and high temperature, it is possible to develop ectopic pregnancy;

Lack of ovulation

Lack of ovulation, when the resulting graph is a set of chaotic points, sometimes elevated, sometimes low, without a clear boundary between phases;

Inflammation of the appendages

Inflammation of the appendages increases the readings of the thermometer, both in the first period of the cyclic process and in the second. In the first half of the graph, an increase to 37° is recorded, followed by a decrease. In the second, what basal temperature before menstruation will be in 2 days, the same keeps on, reaching a value of 38 °.

In the second cycle, with inflammation of the appendages, the basal temperature before menstruation will be kept at 38 °.

Conclusion

You should be aware that when taking oral contraceptives wondering what basal temperature before menstruation is not worth it. Drink hormonal pills distorts the thermometer readings, and the resulting graph will be uninformative.

Basal temperature is an important indicator that can visually display the condition of a woman. The temperature should be measured with strict observance of all recommendations.

Every woman who closely monitors her health should know that her body is completely controlled by hormones. that can influencehuman temperature. Having learned to measure it, you can accurately calculate important days. It should be measured every day, only then it will be possible to draw up a cyclic calendar, it is well guided in cases:

the right time for successful conception
conception
definition of gynecological inflammation
talk about hormonal imbalance
tell about coming soon menses

Laying a thermometer and measuring in the armpits will be ineffective. It is best to measure rectal temperature with a simple electronic pharmacy thermometer and only on the mucous membranes of the body.

The temperature in the intestines should be measured in the supine position immediately after waking up without even getting out of bed. For this reason, the thermometer should be prepared in advance and placed next to the bed. An electronic thermometer will determine the temperature in seconds.

Basal temperature during pregnancy

If fertilization has occurred, the temperature level will have slightly different values. Rectal temperature in the early stages serves as a peculiar way diagnosing conception
If you are completely sure that pregnancy has occurred, then the decrease in rectal temperature from the mark 37 speaks of any threats of disruption
Do not assume that such a measurement of the temperature level - exhausting job. After all, not every woman needs to do this regularly. The temperature is supposed to be measured by those who have repeatedly faced threats and miscarriages in their lives.

The norm of basal temperature before menstruation

Remember that taking medications, drinking alcohol on the eve or not healthy state able to change body temperature.

temperature chart before menstruation

Before menstruation, there is a change in temperature in the female body. You can trace this by noticing a slight increase from 36.6 to 37.6 maximum (that is, one degree). This temperature can be supplemented by some sensations:

breast tenderness
headache
nervousness and irritability

The days preceding menstruation are characterized by increased temperature and these days are the most unfavorable for conception. You can afford unprotected sex because of the low chance of getting pregnant.

measurement in the morning

Remember that basal temperature should be measured lying down. Any activity can break it and mislead you.

If you measure the basal temperature for several months in a row, you can accurately study the characteristics of your body and know exactly the days preceding the menstrual cycle.

When does the basal temperature rise and fall before menstruation?

Basal temperature is a proven gynecological method that has been successfully used for decades and hundreds of years. Hormonal female background (sex hormones) affect how the temperature changes with the advent of each stage of the cycle. Especially importance temperature gains before the onset of critical days.

Temperature data can give a lot of information to doctors, and even to the woman herself, about what is happening with her body. For example, this way you can determine the time of the release of the egg - the time most favorable for conception or even about the pregnancy itself. Not infrequently, the temperature "screams" about the presence inflammatory process or disease. But most often, or rather every month, she warns us about the approach of menstruation.

normal temperature level

As a detailed observation of the female body shows, the body temperature before the onset of menstruation is normally slightly less than the rectal (the one that was measured by the rectal method). This temperature can vary completely, but its value ranges from 36.7 degrees to 37.6 degrees. Before the onset of menstruation, you can notice how it becomes a little lower. This happens yes a couple of days before the start of the discharge
During discharge, a temperature of 37 degrees is considered optimal. It is considered the most acceptable indicator and talks about the normal course of the cycle. But it is not always necessary to focus only on a value measured only once. Here you need to keep a detailed table of measurements every day and take into account strictly all phases, where it is easy to notice the difference in other phases
If before critical days the temperature rises is normal phenomenon because it is the body's response to natural process. It is very easy to understand why this is happening. During ovulation, an excessive amount of progesterone, the female main hormone, accumulates in the female body. It is this hormone that is able to influence the temperature center. which is located in the brain
Commands come from the center of the brain that the temperature should be raised. This happens about a week before the onset of the period itself and only a couple of days (about two) before the onset blood secretions- the temperature drops significantly. During menstruation, the temperature returns to normal

Charts of basal temperature before menstruation

First of all, before you start measuring basal temperature, you should understand how to do it correctly:

the thermometer should be at an accessible distance so that you can get it without getting out of bed
temperature can be measured electronic thermometer(it will be easier and more accurate) or mercury
the tip of the thermometer should be lubricated with baby cream, after which the thermometer is inserted into the anus no deeper than two or three centimeters
the electronic thermometer itself gives you a signal that the value is determined, the mercury must be kept in itself for about five or even seven minutes
you should not make any movements: walk, bend over, squat - this provokes blood flow and the results may not be correct

normal course cycle

Based on this table, you can clearly see how the temperature changes during the cycle. During menstruation, the basal temperature stabilizes to an acceptable state of 36.6 or 36.7. After that, there comes a decline, which every day is able to fluctuate within one degree.

Before the onset of ovulation, the basal temperature gains its minimum value and is kept there for two to three days. After that, the egg provokes a sharp release of progesterone and the temperature rises significantly, rising to 37, 37.1, 37.2 degrees. This temperature is maintained from ten to fourteen days, and only then goes down again before the onset of a new cycle.

cycle without egg release

Graphs of basal temperature during pregnancy

Ovulation is maintained for two to three days and is maintained all this time minimum temperature. After the egg is released, it triggers the release of the hormone progesterone into the body. It is the saturation of progesterone that keeps and raises the temperature.
The following days after the release of the egg are the most favorable for fertilization. You can see how the temperature level gradually rises. However, on the day when the temperature dropped sharply and the next day it rose sharply. most likely fertilization
After this jump, you can notice a significant increase in temperature, which in some cases can reach up to 38 degrees. All this depends on individual features woman's body and health
37.2 is the temperature that indicates the onset of pregnancy

Measurement of basal temperature will allow a woman to determine how smoothly her body works, to determine the exact onset of ovulation for favorable conception and correctly calculate the days in which you can have “unprotected” sex.

Of course the most exact values measurements can only be obtained when the temperature is measured several cycles in a row.

It is normal when the temperature female body fluctuates at a minimum. The female body is controlled by hormones and it is they who are responsible for the decline and growth of thermometer marks. Before menstruation, the temperature rising to the minimum values \u200b\u200bis going down. this is unchanged and it only says that the discharge will begin soon.

IN normal condition it reaches 37, 37.1, 37.2 and even 37.5 degrees. It just depends on how it's set up. female body. Be careful, the temperature increase from 36 degrees to 37 and above should be achieved only when the second half of the cycle occurs.

What does the basal temperature of 38 mean before menstruation?

It is possible that before the onset of critical days, you can observe an increased basal temperature. This may symbolize the presence of any disorders or diseases in the body.

First, check yourself for any inflammatory diseases in organism. They provoke an increase in body temperature in general. If the temperature was observed for only one day. most likely it was ovulation.

high temperature level

The basal temperature, which is kept at levels from 37.1 to 37.5 before the expected discharge and does not subside, indicates the onset of pregnancy. Note, heat at 38 degrees, which is held for more than one day, indicates the presence of disease and inflammation.

Before measuring temperature, pay attention to the following factors:

sex that took place at least six hours before the temperature was taken
Not calm state getting out of bed and moving
alcoholic drinks drunk the day before
taking medication
small and very short sleep

All these factors cause incorrect and incorrect temperature measurements. Movement and sex increase blood circulation in the pelvic organs and provoke an increase in temperature.

If you notice a temperature of 36.9 in the first and second cycle, this most likely indicates that the egg simply did not mature this month. You should not panic here, since ovulation may not occur for several months a year. However, if you trace such a frequency for a long time, you should consult a doctor.

Video: " Basal temperature during pregnancy, before menstruation, during ovulation, measure basal temperature "

Measurement Rules

To use BBT as an informative indicator, it is necessary to observe temperature fluctuations for several menstrual cycles, at least three. Measurement rules:

it is better to measure the temperature rectally - this way the influence of air temperature is less;
the procedure is carried out every morning, including the days of menstruation;
before thermometry, you can’t get up and engage in any activity, so it is recommended to bring down the thermometer and leave it by the bed in the evening, in preparation for bedtime;
indicators are recorded in a notebook, and at the end of each cycle a graph is built (one scale is the day of the cycle, the second is the thermometer readings on that day);
thermometry time - 10 minutes;
it is desirable to wake up at the same time every day;
sleep before measuring BBT should last at least 6 hours;
lack of sleep, alcohol abuse, medication, colds can cause an increase in basal body temperature, so these factors should be avoided.

As you can see, the method requires high motivation and discipline. However, if you have broken a rule, write it down in a note to the relevant day. If on this day the readings deviate significantly from the curve of the graph, they are not taken into account.

BT in the first phase of the cycle

First phase menstrual cycle called follicular, or menstrual.

The first day of the cycle is considered the first day of menstrual bleeding. Usually the temperature in the follicular phase is lowered, is less than 37C in the rectum.

The duration of the phase is about 14 days. The end of the first phase corresponds to the moment of release of the egg from the follicle - ovulation. Before ovulation, BBT normally decreases, and after it increases, which is due to the production of the hormone progesterone by the corpus luteum. The corpus luteum forms at the site of the ruptured follicle and produces progesterone for 10-12 days.

BT in the second phase of the cycle

From the moment of ovulation, the luteal phase begins, it is also the phase of the corpus luteum. It lasts as long as the corpus luteum remains active (12-14 days).

BBT rises after ovulation, remaining about 0.4 C higher than before ovulation for about 10 days. The corpus luteum gradually degrades, and progesterone levels fall. At this stage, 2 scenarios are possible:

1. If fertilization has not occurred during the existence of the egg, that is, the woman has not become pregnant, BT decreases, and after a few days, menstruation begins, and the cycle begins from the beginning.

2. If fertilization has occurred, in the period before menstruation, the basal temperature rises; after that, BT continues to hold on elevated level(about 37 C), and menstrual bleeding does not come.

Changes in BBT during pregnancy

An increase in basal temperature during pregnancy occurs due to the work of the placenta. The placenta, the tissue that connects the mother and fetus, produces progesterone. Thus, although the corpus luteum is no longer active, the high temperature is maintained due to the activity of placental progesterone.

Progesterone continues to be synthesized throughout almost the entire period of pregnancy, but usually the mother's body quickly adapts to such a hormonal background, and the body temperature drops to its usual values.

Thus, if the temperature rises to 37 C before menstruation, and then there is a delay in menstruation, pregnancy can be suspected. However, the fact that body temperature rises before menstruation is not sufficient to confirm the presence of pregnancy.

It should be noted that when analyzing BT, more important role the difference in temperatures before, during, and after ovulation plays, and not the number on the thermometer on the day before menstruation.

That is, if the temperature before menstruation is 36.9 C, and before ovulation it was 36.7 C, this is less likely to indicate pregnancy than the readings of 36.6 C before menstruation in a woman who is characterized by a decrease in readings before ovulation up to 36.1 C.

In the first case, the difference is 0.2 C, and in the second - 0.5 C. That is why BT can be considered as diagnostic sign only if a woman watches her constantly for several cycles.

Factors that raise the temperature

Let's talk about factors that can cause an increase in basal temperature in the second phase of the cycle, and, in fact, before menstruation.

An increase in basal body temperature can also external causes not related to the hormonal background:

Inflammatory processes in the body - viral or bacterial infection, the presence of a focus of inflammation (furuncle, abscess). Symptoms may be mild, especially if the infection is in initial stage or is sluggish.
Gynecological problems.
For example, in women with endometriosis (inflammation of the uterine mucosa), the body temperature rises before menstruation, and is usually 37.0-37.3 C.
In some cases, the temperature rises with severe allergic reactions.
Influence external factors listed in the list of restrictions during the BBT measurement period. These include alcohol use, stress, severe physical activity and overwork, active sex, drug use.

Thus, fever body a few days before menstruation is not a reliable sign of pregnancy.

BT is a good way to monitor the work of the female reproductive system;
the method helps to identify hormonal disorders;
BBT fluctuations throughout the cycle are caused by the work of the corpus luteum, which produces progesterone;
normally, in the absence of pregnancy, 2 drops in temperature are observed during the cycle - before ovulation and before menstruation;
the highest BBT is reached on the day of ovulation, when the egg breaks the follicle;
the absence of schedule fluctuations usually indicates the absence of ovulation;
during pregnancy, BT increases and may remain at an elevated level for several months;
the absence of a premenstrual decrease in BBT is not a reliable sign of pregnancy.

Monitoring changes in basal body temperature (BBT) indicators is used by women as the simplest and most informative method condition assessment women's health. It is especially widespread among women planning a pregnancy. Correct and regular measurement allows you to set the day of ovulation, which greatly increases the likelihood of conception.

Let's determine the normal indicators of BTT before menstruation

The values of basal temperature throughout the entire menstrual cycle are different.

Its fluctuations are due to changes in the level of concentration of certain hormones in different phases:

menstrual phase. Starts from day one spotting, on average lasts up to five to seven days. It is typical for her low level major female hormones.
follicular phase. Counted from the first day menstrual flow, lasts about twelve days. At this stage, the growth of follicles occurs, while one or more of them stand out in size and contain a mature egg. This growth is provided by follicle-stimulating hormone (FSH). In addition, the level of estrogen increases, it is under its influence that the maturation of the egg occurs. The peak of hormone production occurs on the day before ovulation.
ovulatory phase. It starts around the middle of the cycle and lasts about three days. Sharp increase estrogen levels contribute to a jump in luteinizing hormone (LH) - a harbinger of ovulation, FSH level while decreasing. A mature egg is released from the follicle, and the follicle itself becomes the site of growth of the corpus luteum, a temporary gland that produces progesterone.
luteal phase. Its average duration is sixteen days. It is characterized by an increase in the level of progesterone - a hormone that supports pregnancy. If pregnancy does not occur in this cycle, then by the end of the phase, the activity of the corpus luteum fades, the level of hormones decreases and menstruation begins - the beginning of a new cycle.

As a rule, BBT tends to decrease in the follicular phase and increase after ovulation. Temperature 37-37.2°C. is the norm for the luteal phase, while if pregnancy has occurred, then high values \u200b\u200bare stored until postpartum menstruation.

What should be the basal temperature or abbreviated BT before menstruation? Many women dream of a regular menstrual cycle, as this is one of the main signs correct operation reproductive system. One of important indicators is BT. Its daily measurement allows you to control the state of the body, determine the approaching ovulation and the beginning of a new menstrual cycle. Consider the features of testing and interpretation of the results of measuring BT.

BT - indicators that were obtained using a thermometer in oral cavity, vagina or rectally, in anus. The basal temperature during menstruation, before them, and also after it changes.

Promotion or demotion this indicator temperatures are due to the difference in the phases of the monthly cycle:

follicular - the phase of egg maturation, the level of bt will decrease;
ovulation - the fertile phase, during which the onset of conception is possible;
luteal - the phase of the onset of menstruation, when all hormones fall, BT decreases.

During all these phases, the level of hormones in a woman's body is different. Estrogen and progesterone, which is regularly released by the body, affect the change in BBT. And it is on the change in BT that one of the most reliable methods of contraception is built - the calendar method.

Measurement Rules

So, the graph of basal (oral or rectal) temperature is very important, because, relying on the data obtained, the doctor will be able to see a picture of the woman's health and determine whether there are changes in the childbearing system or not.

There are a number of rules for measuring temperature, following which it is possible to obtain the most accurate results:

Temperature measurements must always be taken at the same time of day. Most reliable results can be obtained by measuring BBT in the morning immediately after waking up. Minor deviations in time are allowed - +/- 30 minutes will not negatively affect the readings. perfect time for the procedure, the interval from 6 to 8 in the morning is considered. At the same time, it is very important that before measuring the BT was healthy sleep for at least 4 hours.
Basal or, in other words, rectal, temperature during menstruation is always measured by the same thermometer. If it broke down or stopped showing the correct values and the thermometer had to be replaced, then this must be noted in your notebook, where the readings are recorded.
It is recommended to prepare the thermometer in advance by placing it near the bed. And to carry out freezing without getting out of bed.
The duration of the procedure depends on the method of measurement, but on average at least 5 minutes.
To track the dynamics of changes in BBT, it is necessary to maintain a special chart, which indicates all the indicators for the day, week, month, etc.

bt during menstruation

Studies should begin to be recorded from the first day of menstruation. What should be the BBT before menstruation, for example, a week before menstruation? Indications during this period may be increased, so you can ignore this fact. But on the last day of menstruation, the BT indicator will be about 36.3 ° C and can range up to 36.5 ° C. These are the most favorable conditions for the full development of follicles.

Which BT before menstruation depends on the behavior of the egg: whether conception has occurred or not. When the egg leaves the follicle, a corpus luteum forms at the site of the rupture of the vesicle, which produces hormones to prepare the uterus for implantation of the embryo if fertilization has occurred. And it is this gland that stimulates the increase in BBT on the first day of the delay in order to improve the conditions in the uterus for a more comfortable development of the embryo.

BT a week before menstruation

During this period, the indicators will fluctuate within 37-37.5 ° С. At the same time, one should also take into account such a factor as implantation retraction - when BT drops for a while, and then rises sharply.

If fertilization did not take place during this period, then the level of progesterone gradually decreases, the corpus luteum begins to fade, which leads to a decrease in temperature.

BT 3 days before period

What will be the BT during menstruation and a few days before them, depends on the individual characteristics of each individual woman. According to statistics, on the eve of menstruation, indicators can drop by 0.3-0.5 ° C. The norm for this phase of the cycle are values in the range from 36.8 to 37.1 ° C.

Reasons for changing BT

There are a number of reasons that affect the increase or decrease in temperature:

progesterone deficiency. Leads to a decrease in BBT. characteristic feature this pathological condition is a slow rise in temperature, which will last no more than 7 days. At the same time, the difference in indicators at different phases of the cycle does not exceed 0.4 ° C, and the duration of the second period is reduced to 10 days, which, in turn, stimulates the earlier onset of menstruation.
Endometritis. This disease is characterized by an increase in basal temperature before menstruation - 37 ° C. Such BT lasts until the end of menstruation. And when there is a decrease in BT before menstruation, then in the case of endometritis, these values decrease only by a few tenths of a degree, after which they begin to grow upwards.
The onset of pregnancy. If there is a delay and the temperature in the vagina or anus reaches 37 ° C, but not higher than 37.5 ° C, then most likely there was a conception of a child. If the rapid pregnancy test did not show 2 strips, then it is possible we are talking O late implantation or pathologies - ectopic pregnancy or anembryony.
The onset of the anovulatory phase. A chaotic increase and decrease in BBT indicators may indicate the absence of ovulation. At the same time, the basal temperature graph does not have a clear boundary and the highest point.
The presence of inflammatory gynecological diseases. In case of inflammation of the ovaries, the thermometer records values at around 37 ° C, which will be observed in the first and second periods. At the same time, before menstruation, BT will decrease, after which it will rise again, but already up to 38 ° C.

Also, uncharacteristic readings of basal temperature can be observed in case of failures in hormonal background and disorders of the thyroid gland.

Conclusion

At the end of the publication, let's summarize:

BT is verified gynecological method monitoring the health status of the female reproductive system. Especially important are the values of basal or rectal temperature after menstruation and before critical days, ovulation, more precisely, the dynamics of their growth and decline is important.
According to the BT schedule, it is possible to determine the approach of ovulation and menstruation, to find out if there are any deviations in the functioning of the organs of the reproductive system. Often jumps temperatures signal the presence of an inflammatory process or disease.
There are certain BT standards, deviations from which are characterized by obvious changes in the functioning of the organs of the genitourinary or reproductive system.

At the same time, it should be taken into account that during oral contraceptives, the BT indicators “jump”, so you should not rely on their reliability.

Have you ever checked rectal temperature? Do you or your friends keep such a calendar in order to track the fertile phase and approach menstruation?