Story about Menstruation, Ovulation, and Basal Body Temperature

You may have had menstruation for some years, however, you may not know the mechanism of menstruation and ovulation. When you want to get pregnant, it’s better to have knowledge about these things and basal body temperature.

In this article, we will talk about the mechanism of menstruation and ovulation.

Understanding the mechanism of menstruation and ovulation

The female body goes through menstruation and ovulation in an approximately 28-day cycle. The normal range for the number of days in a menstrual cycle is between 25 and 38 days, with a variation of 6 days or less.

If the menstrual cycle is shortened and the menstrual period occurs within 24 days, it is called frequent menstruation. If the menstrual cycle is prolonged and occurs in more than 39 days, it is called rare menstruation.

The number of follicles in the ovaries, which are the source of eggs, is several million when a baby is firstborn, and gradually decreases as the baby grows. By the first time you have menstruation, there are only 100,000 follicles. The natural selection continues, and when there are no more atomic follicles, you will have menopause. It is estimated that 400 to 500 eggs are ovulated before menopause.

At the time you have menstruation, the pituitary gland releases follicle-stimulating hormone (FSH), which awakens about 100 atomic follicles and causes them to start growing. Although the follicles begin to grow, only one of the 100 follicles, called the master follicle, grows in size, and the others are absorbed.

Once the follicle has matured under the stimulation of FSH, the follicle membrane releases follicle hormone (E2), which is delivered to the hypothalamus. This stimulation causes the egg in the mature main follicle to break through the membrane and fly out of the ovary. This is known as ovulation.

While sperm can survive for about three to five days, the ovulated egg is only viable for about 24 hours. For this reason, people who want to get pregnant need to properly identify their ovulation date and have sexual intercourse.

Follicles that have ovulated or have not ovulated will naturally shrink in the ovary. The ovulated follicle changes to luteinizing hormone (progesterone), which causes the basal body temperature to rise and the high temperature period to continue.

If the ovulated egg is fertilized by a sperm and implants in the uterine lining, you get pregnant. However, if fertilization and implantation do not occur after ovulation, the thickened uterine lining will fall off due to the luteinizing hormone, and menstruation will begin about two weeks after ovulation.

The Meeting of Sperm and Egg

When the egg in the mature master follicle breaks the membrane and shoots out of the ovary, the oviductal vesicle, a sea anemone shaped part of the body, catches the egg and waits in the ampulla of the fallopian tube, the entrance to the fallopian tube. The hundreds of millions of sperm that are ejaculated enter the uterus and travel down the fallopian tubes to the egg.

Unlike the egg, which can only live for 24 hours, sperm can survive for an average of three to five days. With ejaculation, the race for the egg begins, and only one of the first billion sperm to reach the ampulla of the fallopian tube, where the egg is waiting, will be able to fertilize it.

The sperm emits an enzyme from its head called acrosome, which dissolves the eggshell, allowing it to penetrate the eggshell and enter the inside. At the moment of entry, a barrier called the fertilization membrane is put up around the egg, preventing other sperm from entering.

Implantation of fertilized egg and pregnant

A follicle grows in either the left or right ovary, and is ovulated by the secretion of luteinizing hormone (LH). The embryo is fertilized in the ampulla of the fallopian tube and rolls down the fallopian tube, repeatedly dividing its cells, to reach the uterus, where it implants in the softly prepared endometrium.

As the embryo rolls down the fallopian tubes, it repeatedly divides, and on the second day after fertilization, it divides into four, on the third day into eight, and on the fourth day, the division progresses even further, and the cells fuse together, making it difficult to see the dividing cells.

This day 4 embryo is called a mulberry embryo because at first glance it looks like a mulberry seed. A space is created within the mulberry embryo (formation of the blastocoel cavity). The blastocyst is the state in which that space has completely expanded. If the division proceeds smoothly, this will occur on the fifth day. After that, the blastocyst breaks free from the membrane called the zona pellucida (hatching). The embryo implants into the uterine lining.

The embryo implants on day 5-7. After implantation, the embryo produces a root-like structure called a chorion from the outside and attaches to the endometrium. There are some embryos that stop somewhere between the steps of fertilization and implantation.

If this happens, it means that implantation did not occur, and if the embryo hatches and implants firmly in the endometrium, a pregnancy will occur.

Take your basal body temperature

The first thing we would like women who are trying to get pregnant to do is to take their basal body temperature every morning. By taking your basal body temperature, you can roughly predict your ovulation date. Basal body temperature is the temperature of your body when it is in its most restful state, such as while you are sleeping. When you wake up in the morning, you can take your temperature right away in bed or under the covers without moving.

Unlike men, women’s body temperature changes, and it goes up and down depending on the secretion of hormones. It can be divided into two phases: the low temperature phase and the high temperature phase.

The low temperature phase is the period from the start of menstruation until ovulation occurs. The low temperature phase is the period from the start of menstruation until ovulation occurs, and the high temperature phase is the period after ovulation when the body temperature rises due to the secretion of luteinizing hormone. If you are pregnant, the high temperature period will continue, and if the egg is not fertilized or implanted, menstruation will begin around 14 days after ovulation.

If your basal body temperature is normal, you will see a two-phase graph like this, but if your high temperature period is too short, if it does not divide into two phases, or if the lines on the graph are uneven, it is a good indication that there is something wrong with your body, including irregular periods (if the high temperature period persists, pregnancy is suspected).

When the high temperature period is short

The high temperature period begins after ovulation, and normally lasts more than 10 days. If it is less than that, luteal insufficiency is suspected.

When the high temperature period is long

If the high temperature period lasts for more than 14 days, the possibility of pregnancy should be considered. In addition, you may have an ectopic pregnancy or another cause, so see your doctor as soon as possible.

If the graph is not divided into two phases (anovulatory cycle)

Anovulatory menstruation should be suspected. Even if you think you are menstruating properly, there are times when ovulation does not occur and you experience bleeding like a menstrual period, called failure bleeding. The endometrium thickens slightly with trace amounts of hormones, and then it gets old and comes out. Since there is no ovulation, it can be said that there is no change in body temperature.

If the lines on the graph are uneven

If you have been living an irregular life, such as not getting enough sleep or not waking up at the same time, you may have anovulatory menstruation as well as those who do not have two phases.

In some cases, you may simply not be taking your temperature properly, so it’s best to double-check the situation when you take your temperature. It is also possible that the thermometer is faulty, although this is rare.

How to take your basal body temperature

As soon as you wake up in the morning, put the tip of the thermometer under your tongue and measure it. To get a closer approximation of your body’s temperature while you are asleep, do not move and take the temperature in the blanket.

It is important to take the temperature at a regular time. It is convenient to keep a thermometer and a basal body temperature chart to write down your basal body temperature by your bedside table so that you don’t have to get up.

Knowing your ovulation date

The day of ovulation can be roughly predicted by basal body temperature as mentioned above, but it can also be predicted by cervical mucus.

As the follicle develops, estrogen (E2) is released, which causes the cervical mucus to increase. The vagina is kept acidic to prevent the entry of bacteria, but as the day of ovulation approaches, the cervix, which is the pathway for sperm, secretes more alkaline mucus due to estrogen.

As the day of ovulation approaches, estrogen causes the cervix, which is the pathway for sperm, to secrete more alkaline mucus, which encourages the movement of sperm, which dislike acidity. The cervical mucus is characterized by its egg-white consistency and its ability to stretch like a string.


If your basal body temperature changes or your discharge changes, it means that you are close to ovulation or have ovulated. You can also use over-the-counter test strips to measure the level of luteinizing hormone (LH) in your urine to determine your ovulation date. Although it is not as accurate as an ultrasound or blood sample taken in a hospital, it may be a good idea to use it together with your basal body temperature chart as a rough guide to your ovulation date.