5 Cases Where You Could Get Pregnant During Menstruation

Ever been told you won’t get pregnant while you’re having your period? Then, you may be surprised to know it is a possibility! While contraception has come a long way, with easily available methods ranging from female condoms to birth control pills, a whopping 49 percent of all pregnancies are still unintended, as per Centers for Disease Control data.1 This is why it’s critical to know how conception works, including while you’re on your period.

It’s easy to assume you won’t get pregnant during a menstrual cycle. The underlying logic is that since your body is shedding the uterine lining, ovulation or the release of the egg from your ovaries has not happened recently. However, there is a chance, albeit small, that the egg is still viable and could be fertilized by sperm during intercourse, even while you are on your period.


1. Early Ovulation

While an egg shouldn’t normally “live” in your body when you’re having your period, you could ovulate early and get pregnant. As the American Pregnancy Association explains, it is possible to ovulate even without a period occurring. Ovulation itself can be affected by a change in routine, stress, or illness.2

2. Long Lifespan Of The Sperm

Pregnancy during menstruation could also depend on the life of the sperm that has entered your body. A sperm can live far longer in the body than you’d imagine – reportedly, as long as 3–5 days in some instances. If it reaches the fallopian tubes, it could live for 7 days even. If the sperm is viable, it can fertilize the egg even several days after you’ve had intercourse.


This could mean conceiving as much as 3 to 5 days after you’ve had sex even with a regular 28- to 30-day cycle. So even if you ovulate several days later, if the sperm is still alive and well and penetrates the egg, it could cause pregnancy.3 The National Health Services, UK, also points out that if the sperm is in the fallopian tubes, you may be able to get pregnant as late as a week after intercourse.4

So if you’re trying to avoid accidental pregnancy, use a barrier method or any other contraceptive method you would normally use.


3. Short Menstrual Cycle

If you’re someone who has a shorter cycle, say 21 to 24 days, you could ovulate a little earlier in your cycle than women with a standard 28- to 30- day cycle. If that’s the case, you could end up conceiving not just during but even after your period.5 This again is because sperm can live on in the woman’s body for as long as 3 to 5 days in a moist and favorable environment.6 The shorter circle may mean you ovulate faster. So if the sperm is already in, viable, and waiting, the egg that’s released could get fertilized even if a fair bit of time has passed since intercourse.

4. Irregular Periods

It also becomes harder to pin down exact ovulation dates if you have irregular cycles. This could be due to conditions like polycystic ovarian syndrome (PCOS) or other problems like obesity or eating disorders that can meddle with your hormones.7


5. Mistaking Ovulatory Bleeding For A Period

Sometimes, ovulation may be accompanied by a slight bleed also known as mid-cycle or ovulatory bleeding. This can be mistaken for a period. You may then end up having sex at your most fertile time because you think you are having a normal period.8

How To Be More Accurate About Pregnancy During Your Period

If you’ve trying to figure out the sex–period–pregnancy connection, chances are you fall into one of two slots. And this can change how you approach the odds at this time of the month.


For those who want to conceive, the days around the period may not be optimal for the sperm to fertilize your egg. The chances are certainly better at other times of the month.

While it’s safe to have sex during menstruation, you have to keep in mind that having unprotected sex may not be a good idea if you don’t want to conceive. That’s because there are still chances, however slim, of pregnancy under certain circumstances. These are not always easy to predict or detect but while this is not an exact science, there are some ways to be more in control of conception.


Understand Your Cycle

The first step is becoming familiar with your menstrual cycle. Not everyone falls perfectly into the 28- to 30-day slot. In fact, the Office on Women’s Health explains that a normal cycle can vary from 21 days to 35 days. Even the duration before ovulation can go from 13 to 20 days. Most women get their period between 14 and 16 days after they ovulate. Keep in mind the lifespan of the sperm to be sure you do not have unprotected sex around the time an egg is released or for a few days after.9

Chart Period Dates

You should ideally do both of the above along with another step – tracking the exact dates of your period on your calendar. Then, follow these steps to find your fertile period.

  • Pin down the most fertile days by subtracting 18 from the number of days in the shortest cycle you have had.
  • Add this result to the start date of your next period and mark that with an X on your calendar.
  • Now, subtract 11 from the days in your longest cycle and add this number to the start date of your next period with another X on the calendar.

The window you arrive between these two “X” marks will be your most fertile days.10

Track Your Temperature

You can chart your basal body temperature to get a better grip on ovulation dates. Your temperature typically spikes about 3 days before you ovulate and stays high until your period. Remember, this rise is subtle and will need a special thermometer. Watch for changes of between 0.4 and 0.8 degrees Fahrenheit. Your chances of getting pregnant are highest in the 2 to 3 days before your peak temperature (which is when you ovulate), and for between 12 and 24 hours after.11

Check Your Cervical Mucus

You can also monitor the quantity and type of cervical mucus. When it is most wet, clear, and slippery, resembling egg whites, you are most fertile. As it gets cloudy and sticky, your fertility wanes, typically 4 days after ovulation.12