How to Calculate the Fertile Period

Know your fertile period will help her to better understand your body. Find out the days that will give you more chance of getting pregnant.

To better understand what it is and how you can calculate the fertile period, we have to start at the beginning. Every month, all women of childbearing age have a menstrual cycle. A process that starts and ends with menstruation. As a general rule, the menstrual cycle lasts 28 days, however, some women have cycles longer or shorter. It is important to understand the process, get to know your body and know your numbers. It is certain that a month has thirty long days but, in truth, the window of opportunity to become pregnant is very lower.


The organ player of the woman consists of two ovaries, two fallopian tubes, a uterus, and the vagina. The process hormonal, triggered by the glands in the brain, has two functions: ovulation and, in the case of pregnancy, preparing the womb for the fetus. I knew that women have a limited number of eggs? It is the truth. There are about 450 thousand in the whole life, as a general rule, each loop is freed.

In the first days of your menstrual cycle, the hormone FSH “ripens” the eggs. The estrogens from the ovaries increase the endometrium (the cells that line the inside of the uterine wall), creating the conditions for the implantation of the egg once fertilized. About fourteen days before your period, the hormone LH causes the ovulation. At ovulation, releases an egg that once fertilized it follows to the fallopian tubes and implants itself in the uterus.

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If the egg is not fertilized, it breaks down and gives the menses, the start of a new menstrual cycle.


The fertile period varies from woman to woman. Women with regular cycles you know, easily, the date of your next period and can predict the day of ovulation more accurately. The remaining you can also be guided by some symptoms to find your. For both, there are some important numbers to take into account, to calculate your fertile period.

It is difficult to predict the right day of ovulation, however, we know later the exact date that it happened. It is always fourteen days before the first day of menstruation. That is, if the first day of menstruation is day 15, ovulation was on day 1. However, these past data are of no avail to the women who want to get pregnant.


If you have cycles of twenty-eight days, ovulation occurs fourteen days before the date of your next menstruation, cycles of thirty days shall be the sixteenth day, cycles of thirty one days will be the tenth the seventh day and so forth. Then, consider two days for each side and will have a range of five days in which you can be fertile.

The ova have a short life, between 12 and 24 hours. Already the sperm have a longer life, between five to seven days inside the female reproductive tract, if in favourable conditions. Thus, they are more likely to become pregnant if sexual intercourse happen between 24 and 48 hours before ovulation, so that when the egg reaches the fallopian tubes, since there are sperm to receive you.

Therefore, women with regular cycles of, for example, twenty-eight days, ovulate in the middle of the cycle, fourteen days after the beginning of the cycle. That is, if the first day of menstruation was on march 1, the ovulation will be on the 15th of march and the fertile period will be between 13 and 16 march. That is, knowing the date of the next menstruation, just count fourteen days back.

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Some of the symptoms can help you identify your fertile period, the more evident it happens days before ovulation. The cervical mucus changes becoming more elastic and with the look similar to an egg white. This mucus helps the sperm to reach the uterus of the woman.


We recommend that you register in a calendar or on a calendar the dates of their periods, as well as the days on which note changes in your cervical mucus. Today, there are several applications available for all devices, to record these data, like this or this.

Finally, if you are thinking of becoming pregnant, we leave a tip: the quality of the semen is best in intervals of two to three days between ejaculations. So in order to have more chance of getting pregnant, it is recommended that you have intercourse shortly after the end of menstruation, three times per week, every two days.

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