How many days after menstruation can you get pregnant, ovulation on what day

Why is it considered impossible to get pregnant after menstruation?

Even in ancient times, scientists understood that the menstrual cycle is associated with the likelihood of pregnancy. Reasoning about this is found in the writings of Hippocrates, in ancient Chinese treatises on medicine and in other ancient sources. At the beginning of the 20th century, doctors completely decided on how conception occurs, and realized that it was possible for a very short period after ovulation – the release of an egg from the ovary into the fallopian tube. Shortly thereafter, the Ogino-Knaus method (this is the scientific name for the calendar method) appeared.

What the Japanese and Austrian gynecologists proposed can be depicted something like this:

According to adherents of the calendar method, it is impossible to get pregnant during the first seven days of the cycle. From the 8th day after the start of menstruation, you can get pregnant until the 19th day. From the 20th day, the sterile period begins again. These calculations have a sound grain and even a scientific basis, but they are based on the idea of ​​\u200b\u200bthe ideal menstrual cycle and do not take into account many different accidents. And they, as you know, sometimes occur.

What is the chance of getting pregnant immediately after menstruation?

In medicine, there is such a thing as the “Pearl index”. This indicator reflects the effectiveness of various methods of contraception and is equal to the number of unplanned pregnancies per 100 women during the year. If the index for some method of protection is low, this means that the method is effective, if it is high, the method does not work well.

Combined oral contraceptives ² have a Pearl Index of less than 1 (one unplanned pregnancy within a year among 100 random women using this method). Condoms have 2 or slightly higher, taking into account force majeure that can happen to them during intercourse. One of the most unreliable methods of contraception – coitus interruptus – shows an index of 22 ³ . The calendar method even beats him: according to experts, the Pearl index for this method is from 24 ¹ and above, i.e. about a quarter of women who are protected only according to the calendar are convinced of the inefficiency of the method from their own experience.

Here is the answer to the question, what is the probability of getting pregnant after menstruation – very high. All it takes is a small miscalculation, a tiny change in the menstrual cycle, an unusual set of circumstances – and you are faced with a choice of what to do with an unplanned pregnancy.

If you can get pregnant after your period, why do people use the calendar method?

At first, the calendar method was promoted by the Roman Catholic Church. It was believed that believers should not use any other methods of contraception, except for this – natural. Thus, in Western countries, the nickname “Vatican roulette” has firmly stuck to the unreliable calendar method ⁴ . Today the church no longer takes this position, but there are people who continue to use this method for religious reasons.

The method is popular in poor countries for a completely banal reason: contraceptives cost money, and you can look at the calendar for free. To help such women, a special “contraceptive necklace” was developed ⁵ . It looks something like this:

The red bead near the fastener indicates the first day of menstruation, the white beads indicate the days on which the probability of pregnancy is minimal, the blue ones indicate the fertile period. The necklace has a ring that needs to be moved every day.

In developed countries, couples most often practice the calendar method because of the reluctance of men to use condoms, and women to take “hormonal pills”. And, of course, because many are still convinced of the effectiveness of this roulette.

Why can you get pregnant after menstruation?

Because the human body is very complex, and sometimes all sorts of unexpected situations happen. Here are just a few of them:

• In an ideal menstrual cycle, ovulation occurs 14 days before the onset of menstruation ⁶ . In reality, the maturation of the egg in the ovary can begin even in the last days of menstruation, and its release – almost immediately after it ends. The reason for this may be a change in hormonal levels, severe stress and other factors.
• Once in the vagina, spermatozoa find themselves in a highly acidic environment and die within a few hours. However, those that have reached the cervix or the uterus itself can remain alive for up to 3 days, in some cases even longer ⁷ . Thus, it may happen that sexual intercourse took place on a safe day, but tenacious spermatozoa waited for the release of the egg.
• Often women tend to consider any bleeding as menstruation. However, it can also occur for other reasons, such as cervical erosion or too violent sex. Confusing such bleeding with the onset of menstruation, you can very seriously make a mistake in the calculations.

Is it possible to estimate my individual risk of getting pregnant right after my period?

There are a number of conditions that increase the chance of getting pregnant after your period. If you have one of these, you are at higher risk for:

• 

  Irregular menstrual cycle

  If the duration of a woman’s cycle varies greatly from month to month, then ovulation occurs on different days each time. This means that it is impossible to predict what it will be this time – late or early. Because of this, the accuracy of forecasts using the calendar method decreases, and the likelihood of pregnancy after menstruation increases, even if the last time sex on the same days did not lead to conception.

• 

  Very short cycle, less than 21 days

  The shorter the cycle, the closer to its beginning ovulation is shifted. How many days after a short period can you get pregnant? The window between the end of menstruation and ovulation in this case can be reduced to 5 days or less, and, as we have already said, spermatozoa in the reproductive system of a woman can live up to 3, sometimes up to 5 days. As a result, it turns out that there is simply no safe period for a short cycle.

• 

  Prolonged menstruation, more than 7 days

  This situation is similar to the previous one, only the sterility window closes on the other side. The interval between the last day of menstruation and ovulation is reduced due to the long duration of the “red days of the calendar”. The probability of a positive answer to the question of whether it is possible to get pregnant immediately after menstruation, in this case, increases, because the spermatozoa have every chance to wait for the maturation of the egg.

Even if you’ve happily ruled out all of these factors, don’t assume that you or your partner don’t need protection right after your period. Pregnancy should be desired and planned. Until you are going to become a mother, use more reliable methods – barrier (condom, diaphragm, uterine cap) or hormonal (combined oral contraceptives, intrauterine device, and others).