In a normal case ovulation usually occurs 12-16 days before the onset of menstruation. If the cycle is short (21-23 days), it means that ovulation during menstruation or immediately after it is quite possible. Late ovulation is also possible (after the 16th DC), for example, on the 20-30th DC, then women are already expecting their periods. Ovulation from the seventh to the thirtieth day of the cycle is quite acceptable and does not interfere with natural pregnancy — you only need to determine in the right way the release date of the egg.
In this article, we will analyze how ovulation for menstruation is calculated? What does it mean if bloody discharge (spotting) begins after ovulation? How many days after ovulation women have to wait for menstruation? Menstruation goes on the day of the follicle rupture — how to explain this? When to take a pregnancy test?
How to calculate ovulation according to menstruation?
The calendar method for determining ovulation (according to menstruation) is suitable only for women with a stable (regular) cycle.
If the period from the first day of the previous menstruation to the first day of the next menstruation is always firmly the same (± 1 day), then it is easier for you to calculate the fertile period on the calendar. Please read in detail about this detection method in the linked article on ovulationdiary.com.
Formula for calculation ovulation day by menstruation
To determine the date of ovulation, it is necessary to subtract the length of the second phase, which begins immediately after the release of the egg, from the cycle length. For example, a cycle of 32 days, a luteal phase (phase II) – 15 days, then:
31-15 = 16, ovulation will be on the 16th DC.
If the length of the second phase is unknown, it is enough to calculate ovulation day 1 time more accurately. You could also use the average duration of the second phase in the formula (14 days).
The table for calculating the day of ovulation for different cycle times is added in the article. It is enough to calculate your number of days and on the contrary. There will be a possible day for release of the egg (ovulation).
How many days does menstruation come after ovulation?
If the situation with hormones is alright, then menstruation ALWAYS begins on the 12-16th day after ovulation (it’s length is constant for every woman, in most cases 14 days).
Interesting(!): Almost all online calculators use the average length of phase II. But in reality for different women, this number may differ, so there may be a mistake in the date of ovulation. Hence the conclusion — you should not rely entirely on the finished calculator, it is better to calculate your individual length of the second phase once.
For example, if the cycle is 30 days, and the luteal phase is 15 days or 12 days, then the date of ovulation will be:
30-15 = 15th DC, or 30-12 = 18th DC
And the online calculators will always show the result: ovulation occurs on the 16th DC.
Menstruation during ovulation cases
It is assumed that you have precisely determined the presence of ovulation (there was an ultrasound monitoring, positive tests for ovulation on LH, tests for crystallization of saliva, and other reliable methods).
If your usual, normal menstruation ended a few days ago and suddenly there is blood (spotting) again during ovulation, then this is probably ovulatory bleeding, not menstrual.
Ovulatory bleeding is often confused with menstruation. Ovulation spotting is characterized by the following symptoms:
- their usual duration is not more than a day (very rarely two);
- ovary or lower abdomen pain, the lower back aches;
- the discharge is more reminiscent of a light daub of brown or pink color, rather than normal heavy periods, there are no cramps;
- the next day everything passes and the basal body temperature begins to rise above the usual level of the first phase.
Attention(!): For girls who know only about the menstrual cycle in general, I recommend reading this article, in which I explain that ovulation does not necessarily occur on the 14th DC, and if menstruation does not occur at normal times, then this does not mean a missed period.
It may seem to you that these periods began during ovulation, but most often it is ovulatory bleeding. Or you simply incorrectly determined the release of the egg, since normal menstruation comes only 2 weeks after it.
The second possible reason for menstruation is simultaneous with ovulation, when the latter occurs early, during menstruation, on about the 7th DC. Usually during the ovum’s release period the secretions are scarce.
It is important(!): If during ovulation another day or two will be spotted — it is ok. In the case when you have long periods and a small spotting lasts longer than eight days, you need to consult with a gynecologist. Such symptoms may manifest, for example, endometriosis, fibroids, and other problems with a woman’s reproductive health.
To make sure that it was ovulation that occurred during your period, wait 12-16 days (most women have 14 days). After that, menstruation and a new cycle will begin.
Note(!): For those who draw the basal body temperature chart: immediately after ovulation, you will notice an increase in BBT. It will be highly increased approximately two weeks before the next menstruation. This is the normal female cycle.
For more information about ovulation immediately after menstruation, read this very detailed article with pregnancy statistics.
Ovulation test during menstruation
LH tracking by ovulation tests can be used during menstruation. In addition, tests that track the crystallization of saliva (fern effect) will be indicative.
If you have a short menstrual cycle — 21-23 days, then ovulation may well occur already on the 5-11th DC. It is better to start testing with the help of tests for LH from the 3rd DC, when the menstruation bleeding is already weak.
Such a large difference in the estimated date of ovulation is due to the fact that your real luteal phase length is unknown. If you know it, then it will not be difficult to calculate the date of rupture of the follicle. Tests should be taken 2 days before this day to compare the strips in dynamics.
Ovulation immediately after menstruation
In women with a short menstrual cycle of 23 days or less, ovulation occurs almost immediately after the end of menstrual bleeding. The mid-cycle rule does not work here.
It turns out as follows, if the cycle, for example, is 23 days, and the length of the second phase is 15 days, then the day of follicle rupture is 23-15 = 8 DC. Ovulation occurs on the eighth day of the cycle almost immediately after menstruation.
Advice(!): If you are planning a pregnancy, the first sexual intercours should be on the 6th DC, and the next on the 8th, then on the 9th. It means that you will have the highest chances of finding active sperm exactly at the time of release of the egg.
It is logical that if your cycle is about 30-32 days, then the onset of ovulation before the 14th DC is completely excluded, since there simply is no second phase more than 16 days (only in case of pregnancy!)
Late ovulation and menstruation
The term «late ovulation» is called any day later than the standard 14-16 DC. It does not matter on which day of the cycle the follicle ruptured, after this moment the same woman has a constant number of days (from 12 to 16) until the next menstruation.
If ovulation, for example, occurred on the 24th DC — add your length of the second phase (or just 14, this works for most) and you will get the length of your cycle:
24 + 14 = 38 DC, 1st day of a new cycle the day after it
A common mistake(!): If the cycle is irregular and the date of ovulation is not known exactly, it is difficult to calculate when the missed period should begin. Perhaps, at the moment when you think that menstruation should already start, the second phase is still ongoing. That is why everyone who is planning for a baby with an unstable, long cycle, I recommend always calculating the date of ovulation. For non-planners, this article will also be useful — it will dismiss your excessive worries!
Ovulation during missed period
As I wrote in the previous section, very often during an unstable cycle, women think about a missed period, but actually there was no ovulation yet or the second phase is still ongoing. It is believed that a cycle of up to 45 days (ovulation on about the 30th DC) is normal and does not require correction, if everything else is within normal limits.
Here is an example of a pregnant BBT chart, where ovulation occurred at a time when many girls were already waiting for their periods (it is very good that this woman was tracking her ovulation!):
Hint(!): Before talking about the missed period, you need to make sure that ovulation has actually occurred. If you did not track it, wait for your period and from this cycle begin to monitor the release of the egg. Only if you have a superstable cycle (± 1 day) or 100% had ovulation more than 16 days ago — then this is a missed period and you can take a pregnancy test.
If you get pregnant a week before your period, will there be a menstruation
Fertilization is possible not earlier than 12-16 days before the expected date of menstruation. If you expect the next menstruation, based on the calendar method, and not on the day of the actual ovulation, this is not entirely correct, since this method does not take into account spontaneous cycle failures (the egg will come out sooner or later than usual).
When an unprotected contact occurred a week before the expected date of the beginning of menstruation – and the egg was released during this period, then automatically the 1st day of the new cycle (the beginning of the missed period) shifts about 14 days in advance. At least for those who have normal hormones.
This means that there will not be menstruation a week after this ovulation. If spotting began, then this is not menstruation, but possible implantation bleeding. It usually occurs 7-10 days after ovulation.
If, after 2 weeks after confirmed ovulation, spotting (not menstruation) starts and the tests show a positive result (BFP), you need to consult a doctor just in case. If the real, meaning your usual, menstruation began — most likely, the pregnancy failed or it can be ectopic pregnancy.
When to do an HCG test, if conception occurred a week before the expected menstruation
The first ultrasensitive pregnancy test can be done on the 7-8th DPO days after ovulation (the day of the estimated conception).
HCG in the urine appears only after implantation of the embryo, and this happens about a week and a half after fertilization. So, on the 7-10th DPO, the test for hCG can already show a second weak strip.
The first early signs of pregnancy are described in great detail in this article.
Ovulation a week before menstruation — pathology
I remind you that a one-time event, such as confirmed ovulation, and after a weak real period, can occasionally happen due to hormonal failure. Only with their stable repetition, are difficulties with the onset of pregnancy likely.
Here is a chart of BBT with a shortened second phase, only 8-9 days (luteal phase deficiency — treatment is required). It is difficult to maintain a pregnancy if the corpus luteum (produce progesterone), instead of actively working 10-12 days, only works for a week.
When ovulation constantly happens 10 days before menstruation, it is not so critical if there is enough progesterone.
This is interesting(!): A progesterone test is given on the 7th DPO, and not on a specific (for example, 21-24th) day of a cycle, as doctors often prescribe. By the 21-24th DC, it is possible that you also did not have a follicle rupture, what progesterone can you talk about then? The normal level of progesterone in the luteal phase should be in the range of 2.51-25.01 ng/ml.
From experience(!): During breastfeeding (when my daughter was already over a year old), I ovulated several times, and after a week my normal menstruation began. The doctor explained this by the action of prolactin, correction is not required.
«Ovulation before menstruation» — is it possible to get pregnant?
Yes and no! The fact is that the normal distance from ovulation to menstruation is 12-16 days. A shorter distance indicates impaired reproduction.
If the test (or another reliable method of calculation) showed ovulation, and then, after a day, or three or a week, the usual menstruation began — the probability of successful fixation of such an embryo is extremely small, it will come out with blood.
Such cases are rare and not the norm. This requires a mandatory consultation with a doctor for the diagnosis and correction of hormonal levels.
Another thing is if you do not know the exact date of your ovulation and just on the calendar calculate the beginning of your period. If, for some reason, the release of egg occurs later than expected (shortly before the usual period of the onset of menstruation) and there will be SI on these days, then it turns out that the woman became pregnant after having an sexual intercourse «before menstruation».
Pregnancy as a result of early or late ovulation is not different, and develops in the same way as with the standard egg releasing date.
And finally, when calculating the first day of a missed period, rely on the exact determination of the day of ovulation, and not on the calendar. Even women with perfectly even cycles experience sudden malfunctions. Consult your gynecologist if you notice a shortening of the second phase to 10 days or less.
I hope I’ve helped you! Good luck!