Myth or Reality: Can You Get Pregnant During Your Period?
Without prolonging the suspense, the answer to the question "Can you get pregnant during your period?" is: "yes, but it’s really rare." "Unlikely but not completely impossible." It depends on the length of the period and the timing of ovulation, which can overlap in the case of a short cycle, and on the lifespan of sperm. We’ll need to do a bit of math to understand. Don’t worry if math isn’t your strong suit, we’ll help you out.
A Quick Reminder About the Menstrual Cycle
To clarify things, let’s start with a quick reminder about the different phases of the menstrual cycle, during which our fertility changes.
1- The period: it marks the start of the cycle. It can last between 2 and 8 days depending on the woman, with an average of 5 days. During this phase of the cycle, fertility is very unlikely and using a menstrual panty is perfect, as is a menstrual swimsuit.
2- The pre-ovulatory phase (also called the follicular phase): its length varies greatly depending on whether the cycle is short, "normal," or long. For some women, this phase can last less than 10 days or more than 25, but the average is 10 to 18 days from the first day of the period. During this phase, cervical mucus is scarce and fertility is unlikely.
3- The ovulatory phase: it lasts on average 6 days. It is characterized by the production of estrogen and fertile cervical mucus. It includes THE day of ovulation. Fertility is very high during this phase.
4- The post-ovulatory phase (also called the luteal phase): it lasts between 10 and 18 days (14 for a "normal" cycle), until the next period if the egg is not fertilized. It is characterized by the production of progesterone. Fertility is uncertain during this phase.
In theory (and if everything goes well in theory), you cannot get pregnant during your period since ovulation happens much later. But…
The Exception That Proves the Rule
In summary, on average periods last 5 days, ovulation occurs 14 days after the start of the period, and you can get pregnant during 6 days: 5 days before ovulation plus the day of ovulation. But not all of us have clockwork cycles. For many of us, a cycle doesn’t last 28 days but between 21 and 35. And that’s where it gets tricky. Imagine a woman whose pre-ovulatory phase is very short (less than a day, with a short cycle), whose ovulatory phase starts on the 6th day of the cycle, and who has her period for 7 days. She could potentially get pregnant during her period, since her fertile window starts on day 6 and her period ends on day 7. Headache? That’s normal. But it’s almost over.
The Lifespan of Sperm in the Vagina
Yes, we just saw that for some women there can be a small fertility window during their period in the case of a short cycle. Now let’s see how sperm take advantage of this. In the male body, these tiny reproductive cells can survive 2 months in warm conditions without ejaculation, while they die quickly in open air. And in the female body, for example at the entrance of the cervix, some can quietly go into standby after unprotected sex, waiting for the egg to be released. In this situation, they keep their ability to fertilize for up to 5 days. And can turn our egg into a zygote!
Let’s Stay Vigilant
So here is a scenario, very rare according to statistics, where a woman can get pregnant during her period. That’s why when using a natural contraception method, it’s important to know your cycle inside out and if you’ve chosen to use a condom, to keep using it even during sex during your period. Observing cervical mucus can sometimes be hidden by menstrual blood flow.
Finally, some bleeding caused by a rise in estrogen can be mistaken for a period (#spotting), be careful: it can correspond to a very fertile period.
By Élise
