What is the likelihood of getting pregnant on your period

Can you get pregnant if you have sex while you are in your period?

Yes — it’s possible to get pregnant if you have unprotected sex during your period. However, it’s less common for this to happen.

Here’s the deal: A woman is most likely to get pregnant from sex that happens just before and during ovulation (when an egg is released). Ovulation happens in the middle of the time you get periods, usually about 14 days before your period starts. It’s more likely that you could become pregnant from sex during your period if you have a shorter menstrual cycle.

All of this might sound really complicated, especially if you aren’t sure how long your menstrual cycle is, or when you’re ovulating. During the first few years that you have a period, it’s pretty typical for your menstrual cycle to be irregular — which makes this stuff even harder to keep track of. But if you use a birth control method like condoms or the pill (both is even better) every time you have sex, your chances of getting pregnant are really really low, whether you’re on your period or not.

Tags: periods, ovulation, am I pregnant, sex during period

Your period came, so does that mean you can be a little more lax about birth control? After all, you can’t get pregnant while Aunt Flo is around, right?

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Unfortunately, that’s not true. You can get pregnant during your period.

• If you didn’t ovulate in the middle of your cycle.

• If your periods aren’t regular — so you don’t ovulate regularly.

• If you have a short menstrual cycle.

It’s not quite that simple, says Ob/Gyn Amy Stephens, MD. She clears up the confusion about fertility and your monthly cycle.

Fertility windows

The most fertile time of your cycle, when you are most likely to get pregnant, is when you ovulate, or release an egg, Dr. Stephens explains. That typically happens midway between periods.

So if you have a regular 28-day cycle, Day 1 would be the first day of your period, and you would ovulate around Day 14. “You have the highest chance of getting pregnant during the few days before and after that day,” she says.

But that’s a general guideline and not a rule. “You can definitely get pregnant outside that window,” Dr. Stephens says.

Ovulation timing

If you have unprotected sex during or right after your period, there is a lower chance of getting pregnant. “But the chances are not zero,” Dr. Stephens stresses.

That’s especially true for women with irregular periods, whose ovulation date is harder to predict. Even women who normally have periods like clockwork can experience an unpredictable cycle as the result of things like stress, hormonal changes, and losing or gaining weight.

Having a shorter-than-average cycle also increases your risk of conceiving during period sex. That’s because sperm can live inside you for up to 5 days. They could still be hanging around, looking for love, if you release an egg 4 or 5 days after your period ends.

How not to get pregnant

If you want to get pregnant, plan to get frisky halfway between periods for the best chances. But if you’re trying to avoid pregnancy, don’t use your period as a guide. Instead, choose a reliable form of birth control.

“That’s the best way to prevent pregnancy,” Dr. Stephens says. 

Yeah, you probably already knew that. But now you know the whole story.

Despite popular belief, it’s still possible to get pregnant during your period, and birth control is still necessary to prevent pregnancy. This is because it’s difficult to predict exactly when ovulation will occur.

Can you get pregnant while on your period?

The chances of getting pregnant while on your period are low, but pregnancy is still possible.

The answer lies in understanding the fertile window. For people who are trying to get pregnant, menstruation is not the best time to conceive. Getting pregnant depends on ovulation, which happens when an egg is released from the ovary and moves toward the uterus. The day of ovulation varies from one person to another and from cycle to cycle.

Although the chances of getting pregnant while on your period are low, there are exceptions. For example, it is possible to conceive during a period if ovulation occurs early in your cycle or if your periods last longer than five days. 

The chances of becoming pregnant during menstruation are higher for people with shorter monthly cycles. Shorter cycles (21–24 days or fewer) mean ovulation occurs early in the cycle. Because sperm can live for up to five days inside your body, having sex near the end of a period could lead to pregnancy if ovulation occurs early (within that five-day sperm survival window). 

Generally, most people ovulate sometime between days 10 and 17 of their menstrual cycle. The earlier ovulation occurs, the earlier the fertile window will start. The fertile window begins five days before ovulation. If ovulation occurs on day 14 of a cycle, then the fertile window starts on day nine. But if ovulation occurs on day eight of a cycle, the fertile window begins on day three — possibly in the middle of a period. 

Not all fertile days are equal. The days closer to ovulation have higher chances of pregnancy than the ones further from ovulation. 

Having unprotected sex a day before ovulation typically results in about a 30-percent chance of pregnancy. Having sex five days before ovulation involves about a 10-percent chance of pregnancy. This means that even if ovulation occurs early enough to start in the last days of your period, the possibilities of becoming pregnant on these days are not high.

Can you get pregnant right before your period?

The chances of getting pregnant right before your period are extremely low. For people with regular cycles, ovulation likely occurs 10–16 days before the next period. The eggs released during ovulation can only be fertilized for 12 to 24 hours.  

Сonception is least likely on the days before a period starts.

About 24 hours after ovulation, the chances of becoming pregnant start to decrease. The more days that pass after ovulation, the lower the chances of conception become.

Can I get pregnant the day before my period and still have a normal period? 

This is a question Flo users often ask, maybe because of the misconception that it’s not possible to get pregnant during a period. 

You can't get pregnant a day before your period, as ovulation will have occurred 10-16 days before the period (and not one or two days before).

Regardless of when conception happens, periods stop. 

Nevertheless, some people experience spotting during ovulation and mistake it for period blood. In fact, ovulation is the most fertile day of a cycle. Having unprotected sex during ovulation spotting can result in pregnancy.

Sometimes, people may also mistakenly assume implantation bleeding (spotting) is just a period. Actually, implantation bleeding is an early sign of conception.

Can you get pregnant right after your period?

Yes, it is possible to get pregnant right after a period if the fertile window starts immediately after menstruation ends. Sperm can live for up to five days inside the body. If bleeding stops on day six, sex happens on day seven, and ovulation occurs on day 11, the sperm from day six may still be in the uterine tubes. In this case, pregnancy is still possible. The likelihood of pregnancy after a period increases with every day after bleeding has stopped. 

For people trying to conceive, this can be an ideal time to try. Having sex every day increases the chance of conception.

Best time to get pregnant after a period

The likelihood of becoming pregnant is highest during the two days before ovulation begins or exactly on the day of ovulation, when an egg is released from the ovary. Usually, ovulation happens about two weeks (10-16 days) before the start of the next period. Cycles and ovulation dates vary, so you may want to try an efficient method of predicting ovulation to improve the chance of conception.

Here are four methods for predicting ovulation; they can help you find the best time to get pregnant after your period:

1. For regular cycles with the same number of days each month, an ovulation calculator can help determine the most fertile day of the month. 
2. Tracking the signs and symptoms of ovulation, like changes in basal body temperature and cervical mucus, can also help determine the best time to get pregnant after your period.
3. Use ovulation predictor kits to pinpoint egg release.
4. Log your menstrual info in Flo and predict your fertile days using our AI-enhanced algorithms.

Can you have a period and still be pregnant?

No — once pregnancy begins, the uterine lining no longer sheds each month. Once the body starts releasing a hormone called human chorionic gonadotropin, monthly periods will stop. However, some people experience light bleeding after conception, around the same time their period would have started. This is called implantation bleeding. 

If you’re pregnant and experience bleeding or spotting, contact your health care provider.

Birth control to avoid getting pregnant on your period

Pregnancy can occur even if you’re on your period. To avoid pregnancy, it is important to use contraception.

Birth control methods that can prevent pregnancy on your period include:

• Male condom
• Combined oral contraceptive pill
• Progestogen-only pill (mini-pill)
• Contraceptive patch
• Long-acting reversible contraception, like an implant or intrauterine device

Updated on January 19, 2021

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“Implantation Bleeding: Normal in Early Pregnancy?” Mayo Clinic, Mayo Foundation for Medical Education and Research, 9 May 2019, www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/implantation-bleeding/faq-20058257.