Well theoretically the answer is yes but the likelihood is very very low.
The typical female menstrual cycle is 28 days. This is counting from the 1st day of the menstrual bleeding, which is considered Day 1 of the cycle to the 1st day of the next menstrual cycle. Each day thereafter is considered Day 2, Day 3, Day 4 and so on.
Classically a woman ovulates about 14 days before her expected menstrual bleeding.
What do we mean by ovulate?
Ovulation refers to the release of an egg from the ovary. If this egg meets a sperm that is available in the uterus then fertilisation happens and a foetus starts to form over time.
Ovulation varies based on a woman’s cycle. Some women have a longer cycle of around 35 days between periods so these women typically ovulate on Day 21 of the cycle. Women with a shorter cycle of 21 days ovulate around day 7. You get it , its as we said about 14 days before the next expected period.
If you are curious about your cycle and ovulation, you can start by charting the 1st day of your period flow and continue to chart the start of your next period again. Do this over 3-4 months and you will get an average of what you
length of your cycles are like.
Let’s say with your charting you had 30 days between your periods then with the next cycle it was 32 days then the following one was 28 days, what you do is total up the 3 duration in other words 30+32+28 =90 and then divide this by 3, so your average is 30 days! 30 days is then your cycle length.
Remember you are not mechanical robot! It’s not going to be exact each cycle. Please allow for a few days variability don’t panic if it’s off by 3-5 days.
So now that you know roughly when you might ovulate let’s then talk about the sperms.
Rule number 1 : Sperms can last for about 5 days.
So if you have a short cycle eg. 21 days only it would means that you will ovulate at Day 7 (remember 14 days before your expected period) and if your menstrual flow lasts about 5 days and you have sex of Day 5 of your cycle while you are still having a little bit of your period, then if the semen is deposited in your vagina (in other words ejaculation happens in your vagina), they will survive for up to 5 days, giving the semen a chance to meet the egg in the uterus leading up to a potential fertilisation and hence pregnancy! Phew!
So that’s how it’s possible to get pregnant even if you have sex on your period – it really does depend on what your cycle length is like.
Anyways, side note for all my lovely period frantic ladies: it is normal for a period cycle to vary between 20 to 40 days. No need to get alarmed if you if have a 40 day cycle. If your cycle exceeds 45 days then there can be a correlation with reduced fertility.