Which cycle day is ovulation on and how to calculate it?

Women’s ovulation (in simple words) is the release of a mature egg from a follicle , ready for fertilization when it meets a sperm. Ovulation occurs 12-16 days before the onset of menstruation (the most have 14 days before). If the cycle is regular, then the day of ovulation can be calculated as follows: number of DC minus 14.

In order to get pregnant, you need to calculate the day of ovulation. The highest chances for impregnation will be if intimacy takes place on the day of ovulation and a day or two before it. This is the period of maximum fertility.

In this article we will talk about what ovulation and the menstrual cycle mean. How does the reproductive system function? What are the phases of the cycle? And how to calculate your individual fetal period.

How to calculate the menstrual cycle 

The cycle begins on the first day of the onset of menstruation – this is the first day of the cycle (DC). It ends on the day before new periods – the last day of the cycle.

For example, the bloody vaginal discharge began on the 5th, and the next menstruation began on the 31st. So the 5th is the first DC, the 30th is the last. The menstrual cycle is 26 days.

Note(!): If the menstruation (bloody discharge of the ruby color) does not start immediately, but after 2-3 days of a brownish spotting, you need a gynecology consultation, because endometriosis or another gynecological disease is possible here. This can prevent pregnancy.

Tip: If in the evening you notice that the discharge has turned a little pink, this is not the first day of the cycle. Start the countdown from tomorrow, when you certainly can not do without a sanitary towel (this will be the first DC).

The duration of the menstrual cycle – what is normal

A healthy woman who is able to become pregnant and have a baby, the duration of the menstrual cycle is usually from 21 to 35 days. 12-16 of them are the phase of Corpus Luteum, the remaining days are the first phase. Everything that is more or less than 21-35 requires a medical diagnosis.

It is interesting to know(!): There are longer cycles with the onset of normal pregnancy. But still, imagine how long you will need to wait for the day of ovulation for every new cycle. Moreover, in such situations there is no guarantee that it generally happens.

I phase – follicular 

So, the cycle begins on the first day of menstruation and consists of two phases: follicular and luteal (phase of Corpus Luteum). Follicular because during this period a dominant follicle with an egg inside matures. Luteal because in this phase a Corpus Luteum forms under the influence of luteinizing hormone.

After the periods termination, the hormone FSH (follicle-stimulating) is produced in the pituitary gland. It: 

  • helps to restore and build up the uterine epithelium; 
  • stimulates maturation in the ovary of the follicle.

The importance of this period is that under the action of hormones from one of the ten follicles in both ovaries, one will be chosen as the dominant one, which will grow to give a mature egg.

Interesting to know (!) Many people think that an egg develops and becomes ready for fertilization only within a few weeks. That’s not entirely true. The female reproductive cell begins its development long before that – it takes about 3 months. Exactly for this reason it is recommended to take measures to improve the quality of the egg one quarter before the start of active operations.

How to increase the ability of an egg to fertilize

There are many factors that negatively affect the largest (and the most important!) cell in our body. The most aggressive of them are free radicals, smoking and alcohol. They cause premature cell aging, various chromosomal abnormalities, due to which the egg is not fertilized, and the embryo subsequently stops in development. Here are your most important actions:

  • Stop smoking and drinking any alcohol. 
  • To eat processed (created at the enterprises) ready-made food and semi-finished products. 
  • You should have vegetables and fruits of bright colors, as well as greens, nuts and dried fruits on your table every day.

    The follicular phase - various stages of the follicle's development at a woman
    The follicular phase – various stages of the follicle’s development at a woman

Note(!): The duration of the first phase can be different even for the same woman. That’s exactly why when planning it is necessary to accurately determine the period when ovulation begins. There are many very good methods for this. I tried them all and over the years of planning I learned thoroughly how the body responds to the jump of LH and estrogen before ovulation.

Ovulation (oocyte release) 

Ovulation divides the cycle into two phases. Most often it occurs in the middle of the menstrual cycle, or more usually 14 (12-16) days before the start of menstruation.

A signal to its onset is a sharp increase in the level of LH (luteinizing hormone). The peak of LH does not always match the moment of egg’s release, and the ovulation tests give a positive result 6-48 hours before this moment.

Note(!): Determining the favorable period for conceiving by tests on LH is considered to be one of the most accurate calculation methods. More reliable, one hundred percent is only through an ultrasound (folliculometry).

At the time when ovulation begins, a mature egg is released from the opened follicle. If you listen carefully to the body and understand the signals it gives, you can even physically feel the beginning of ovulation and notice obvious signs.

For many women (and for me too) it is known to be the feeling of tingling in the lower abdomen or a slight soreness that occurs during ovulation, thereby subjectively confirming it.

From experience (!): Basal thermometry is one of my favorite methods of self-diagnosis. Anyone who has mastered a few simple rules for measuring BBT can evaluate literally through the eyes how the phases of the cycle change. Are there any problems with ovulation, the second phase? And also to catch the first signs of pregnancy.

Here is one of the characteristic signs of the onset of pregnancy: Decrease of the basal temperature for 0.2-0.4 °C  or 0.36-0.72 °F (implantation dip) with a sure rise on the next day about a week before menstruation.

Ovulation duration 

The period of ovulation for women is a short interval of the menstrual cycle, which lasts 24 hours. The egg leaves the ovary during ovulation, getting down the Fallopian tube. It moves to the uterus, ready to be fertilized.

Right now, the presence of sperm in the body of a woman is necessary for conceiving. If it occurs, after a few days the fertilized egg (zygote) will attach itself to the uterine wall (will be implanted) and so the pregnancy will start.

It is important(!): Knowing your approximate egg release period, you can prepare for it in advance. For example, intimacy two days before ovulation, and then another day later, will provide the presence of sperm at the right time and in the right place.

Does every cycle have the ovulation?

Women under 35 years of age (on average), have two or three anovulatory cycles during the year (here’s a detailed article about cycles without ovulation on OvulationDiary.com). Later, the number of such cycles increases. This is a common physiological phenomenon when a dominant follicle does not form in the ovaries and according to this there is no ovulation.

If you have an unstable cycle, especially when there is no menstruation for a long time – 35-45 days or longer, you need to check whether there is generally ovulation. I recommend to start from the visit to the doctor and folliculometry.

At home, you can track fertility by the following ways: ovulation tests, saliva crystallization and basal temperature measurements and others.

Is it possible to get pregnant before ovulation?

The favorable period for impregnation is three to four days before ovulation occurs. The day after it is also favorable, but a woman has particularly high chances to get pregnant a day – two before or on the day of ovulation.

Everyone who dreams about a child needs to know exactly the correct day of ovulation and try to ensure that sexual congress takes place on these days. Medical statistics determine the chances of getting pregnant on different days of the cycle as follows:The probability of becoming pregnant on the day of ovulation and the days before and after it

The end of the ovulation: what happens to the egg

If fertilization has not occurred, the egg loses its viability, collapsing in the fallopian tube within 24 hours. Having a successful fertilization, the zygote moves toward the uterus for implantation.

How many days after ovulation is it possible to get pregnant?

Coming off the safe days after ovulation depends on how many days an egg lives. According to medical sources, on average, an egg is viable for 24 hours, hereupon it will collapse.

The most persistent sperm retains fertility within 3-5 days after sexual congress. Thus, the day after ovulation, the probability of conceiving is still there – but then the chances of getting pregnant are extremely small.

II phase – luteal 

After the release of a mature egg, the corpus luteum phase, or luteal phase, sets in. It lasts until the beginning of the next menstrual period (first day of menstruation). 

After the female cell exits the follicular vesicle, its walls close up like flower petals. The process of accumulation of fats and the formation of yellow pigmentation begins.

During this phase, the woman’s body prepares to carry the fetus.

The corpus luteum is responsible for the production of progesterone that supports pregnancy
The corpus luteum is responsible for the production of progesterone that supports pregnancy

The corpus luteum actively produces the hormone progesterone, which is important during the pregnancy. It: 

  • stimulates the preparation of the inner uterine layer for attachment of the fetal egg; 
  • provides the growth of endometrial vessels (uterine epithelium), strengthening blood circulation in the upper layers of the uterus.

Thanks to progesterone, a fertilized egg successfully attaches to the uterus and an embryo develops.

On what day of the cycle is there the ovulation

All women have a different ovulation day. It depends on the individual duration of the first phase. Normally, ovulation occurs from the 7th to the 30th DC, but there are cases of normal pregnancy among the women with a longer cycle.

Note(!): The same woman has the constant duration of the second phase, the deviation is a maximum of 1 day. If the periods are regular – it is easy to calculate the exact day of ovulation. It is rather simple to take away the duration of the luteal phase from the first day of the next menstruation.

And if your cycle is 28 days – this does not necessarily mean ovulation will occur on the 14th DC. It all depends on the duration of the luteal phase. If a woman has the phase of the corpus luteum 16 days, then having a 28-day cycle, follicle rupture occurs not on the 14th (as many believe), but on the 12th DC.

Note(!): To determine the exact length of the phase II – determine your day of ovulation by ultrasound, tests for LH or crystallization of saliva. Wait for the periods start and count the days between ovulation and the first day of menstruation. This will be the duration of the luteal phase.

Table for determining the day of ovulation, if the cycle length is from 21 to 45 days

Ovulation day according to the length of the cycle. The luteal phase is 14 days, or 12-16 days
Ovulation day according to the length of the cycle. The luteal phase is 14 days, or 12-16 days

In order to determine on which day of the cycle you have ovulation, select your cycle duration (the first column) and find out the most probable day of ovulation (the second column), and also the normal acceptable range, if your second phase is 12-16 days.

Multiple ovulation 

Sometimes in the days before ovulation, not one but two dominant follicles can be formed, one in each ovary. This leads to the fact that at the same time or at different times two sacs can stand out. In rare cases, even several eggs mature during one menstrual period.

Normal ovulation involves the release of 1 egg, but there is also a double ovulation, leading to the birth of twins.

Note(!): The birth of twins occurs as a result of double ovulation and the babies can be heterosexual and unlike each other. If division of one egg occurs, identical twins are born, who are very difficult to be differed in appearance. The cause of double and even multiple ovulation is through a genetic life cycle, hormonal therapy or drug stimulation.

Early and late ovulation 

The rule is simple, if your ovulation is before the 14th DC it is an early ovulation. There is nothing wrong with the fact that the UC releases, so to say, on the 7-10th DC (as in the 21-23-day cycle). There is also late ovulation, occurring later than the 14th DC. These delays in a case of a successful conceiving in no way affects the course of pregnancy.

Early and late ovulation is determined by the rate of maturation of the dominant follicle (the first phase), and the second phase is always the same. Some women have this speed different from cycle to cycle – an irregular cycle. There is a very detailed article, how to plan having an unstable cycle.

If you do not want to determine the day of ovulation 

To maximize your chances for impregnation and not to bother with calculating the sacs, keep to the rule of intimacy every two to three days.

Sperm cells generally live up to three (sometimes longer) days. Thus, active sperm cells will always be present in your body to fertilize an ovum at the right time in the cycle.

Of course, there are many factors besides ovulation that ensure pregnancy. That is exactly why I recommend finding out what can prevent your pregnancy (and what should be done) before starting active planning. This way you can save an abyss of time (for example, it took me no less than 6 and 5 years to get pregnant).

I hope the article was helpful to you. I wish you a quick and happy pregnancy!

Which cycle day is ovulation on and how to calculate it?