Can You Get Pregnant While On Your Period? A Doctor Weighs In

There needs to be more open discussions around women’s health care—especially when it comes to female fertility and the topics that confuse us. In our opinion, no topic should be considered “taboo” or off the table when it comes to our health. That’s why we want to address common questions head-on, like, the common query: Can you get pregnant while you’re on your period?

The question has been a conundrum for many women. It’s a topic that has sent pregnant rumors around many a high school health class for years, and TBH, we’ve never felt like we got a clear answer. So, in order to finally put the query to rest, we spoke with Alyssa Dweck, M.D., a New York-based gynecologist and the author of the book The Complete A-Z For Your V. Here’s what you need to know about the possibility of getting pregnant while on your period—because we know you’re wondering just as much as we were.

Can I get pregnant while I have my period?

We’re not going to beat around the bush here. The short answer is yes, you can absolutely get pregnant on your period. The longer answer is that there are many factors that determine how likely it is that you successfully conceive during a menstrual cycle. While studies show that the chances of you getting pregnant on your period are lower than other points in your cycle, Dr. Dweck explains that it really depends on your own personal body.

“It’s important to note that not all vaginal bleeding is your period,” says Dr. Dweck, which is something that can make tracking your cycle (and therefore trying to track a pregnancy) tricky. “If you’re on your period and your uterine lining is shedding, you’re not going to get pregnant,” Dr. Dweck says. “However, there are many nuances to this because many women have irregular periods (due to hormonal birth control, like an IUD, for example), and they may not realize they still have the potential for getting pregnant.”

Other causes for vaginal bleeding include a hormonal imbalance, thyroid irregularity, structural issues, abnormality of the cervix, vaginal infection, and even ovulation, which is when you’re the most fertile. All of these can easily be mistaken for a period, and having unprotected sex—especially during that ovulation window—could dramatically increase your chances of getting pregnant. Additionally, your chances of pregnancy actually increase later in your period (on your last or second-to-last day of bleeding) because you’re closer to approaching that ovulation window.

Being conscious of your ovulation is key since Dr. Dweck says that’s the time you’re most likely to get pregnant. “When you’re ovulating, your ovary is sending out an egg,” Dr. Dweck explains. “After that, you have a 72-hour (three-day) window of when you could get pregnant.”

On top of that, sperm can live up to five days inside the female body. That means if you have sex while you’re on your period and you don’t have a regular cycle, you might ovulate shortly after you finish menstruating.

The issue with relying on having sex while you’re on your period to avoid pregnancy is that it isn’t a totally reliable method of birth control. “If you’re someone with really erratic bleeding, you can’t really know if you’re bleeding is due to an egg not being fertilized or something else,” says Dr. Dweck. “So, the bottom line is it might be unsafe to have sex during that time.” In short, unless you have a perfect 28-day cycle and have been diligently tracking it, you could be risking pregnancy by having sex on your period.

Can I track my period to prevent unplanned pregnancy?

Whether you’re trying to get pregnant or avoid it, Dr. Dweck highly recommends getting to know your body and your unique cycle. Once you know what’s normal for you and your body, you can make better decisions about your health and potential birth control methods.

“It’s really helpful to get to know your own cycle,” Dr. Dweck tells HG. “If you have your period every 28 days you can predict exactly when you’re ovulating, but even if your cycle is slightly shorter or slightly longer, you should be able to determine a pattern.”

If you’re interested in tracking your cycle, Dr. Dweck recommends several period tracking apps, like Period Tracker or Clue. She also recommends looking into fertility apps, but be aware that they’re meant for finding the best time to get pregnant, not avoiding pregnancy. Additionally, she notes that while these apps might offer peace of mind should you choose to participate in unprotected sex, they’re not fool-proof, and there’s still a chance you may become pregnant.

Instead the only way to be sure to avoid unplanned pregnancy is to use birth control.

“If you’re on birth control, the period typically occurs at a very predictable time,” Dr. Dweck tells HG.

She tells us that being on birth control such as the pill gives you protection that is 98 to 99% effective. “Unless you missed a pill or are very unlucky you will not get pregnant when you’re on the pill,” Dr. Dweck says. You can also choose to use condoms as your preferred birth control method. When used correctly every time you have sex, male condoms are proven to be 98% effective at preventing pregnancy.

So while having sex on your period isn’t a surefire way to avoid getting pregnant, these methods are. Particularly if you’re not planning on making a new addition to your life any time soon, it’s better to learn as much as you can about your body, because you don’t want to play with the odds. To prevent pregnancy every time, be safe out there, and always use protection.