7 Period Facts Everyone Should Know

Here's what you need to know about menstruation

Period facts are often obscured by myths about menstruation. A menstrual period is the monthly shedding of the uterine lining. Most girls get their first period between the ages of 10 and 15. Women continue to have their period until their late 40s or early 50s.

In the past, periods were only talked about in whispers, if at all. A girl typically learned about menstruation from her mother or girlfriends. However, much of what was passed down was based on cultural beliefs. Talking about periods in mixed company was taboo.

Today, women are more open about menstruation, but some period facts still have been obscured.

This article discusses period facts and myths. It answers questions about what a woman can do during her period and what she shouldn't do. (Spoiler: There isn't anything you can't do when you have your period).

common period myths debunked

Verywell / Lara Antal

Period Fact: You Can Bathe on Your Period

Some people think a woman shouldn't take a bath or shower when she has her period. Some even think she shouldn't wash your hair. This is not true. There is no reason not to bathe during your period. In fact, a warm bath can help ease cramps.

It may seem hard to believe, but in generations past, women were told they could get sick, go blind, or lose their hair from taking a bath during their menstrual period. None of that is true, but some of these inaccurate myths have been passed from one generation to the next.

Period Fact: You Can Swim on Your Period

It is safe to swim during your period. The old belief that you should stay out of the water during your period may have started before tampons or menstrual cups were popular. 

Swimming without feminine protection is unhygienic. Any body fluid, including blood, urine, or feces, can contaminate a swimming pool.

As for swimming in the ocean with your period makes you a target for sharks: That is definitely an urban legend. There is no evidence this ever happens.

Period Fact: You Can Exercise on Your Period

The belief that you should avoid exercise while on your period comes from a very old idea about menstruation. Menstruation was once treated as a sickness. Menstruating women stayed home. They rested and did not talk to anyone. 

This idea might be based on old cultural views. Menstruation is normal. It is not a disability. Your period should not stop you from doing things you do at other times. It is safe and healthy to exercise while on your period. In fact, regular exercise can help relieve cramps.

Pain medication can help if your cramps make it hard to exercise. Athletes often compete during their periods, even Olympians.  

Period Fact: You Can Have Sex on Your Period

The misunderstandings about sex during menstruation have cultural roots. Some religious texts don't allow sex during menstruation, and some cultures believe that men can be contaminated or harmed by any interaction with menstruating women. This is not true.

It's perfectly fine to have sex during your period. You may feel uncomfortable about having sex on your period due to the potential mess. It is perfectly fine to wait until after your period if you or your partner feel this way.

Sex on your period is not unhealthy, though. It may even help relieve cramps. If you choose to, having sex on your period is fine.

Period Fact: You Can Still Get Pregnant

It is possible to get pregnant during your period.

You need to ovulate (release an egg) in order to get pregnant. That usually happens after your period is over. Sometimes the time when you are fertile may overlap with your period. This can happen any month, but it's more likely if your periods aren't regular or if you bleed longer than average.

Unless you use birth control like the pill or an IUD or meticulously use natural family planning methods, assume there are no safe days to have sex without the chance of pregnancy.

Remember, most birth control methods do not protect against sexually transmitted diseases. It is always best to practice safe sex.  

Period Fact: Girls Can Use Tampons

You can use tampons during your first period. It's important to insert them the right way, though. Read the instructions first. Your tampon should not pinch or hurt. You will not feel it if it is put in the right way.

In the past, people thought virgins should not use tampons, but that is not true. Using a tampon does not cause a woman to lose her virginity and will not cause the hymen to break.

Period Fact: Periods Don't Necessarily Synchronize

Some people believe women who spend a lot of time together have their periods at the same time. This is still an open question.

In the 1970s, research suggested that women who lived together had their periods at the same time. Researchers thought this was caused by body chemicals called pheromones.

Later research pointed to period synchronization as a random event. The idea won't go away, though researchers are still trying to explain it. Until there is more evidence, this will still be an unknown question.


We understand more about menstruation today than we did even in the recent past. Some activities were once considered taboo during menstruation, like bathing, exercising, and having sex. Today we know that these activities are healthy and may even help with period cramps.

Other facts are especially important to understand. For example, it is possible to get pregnant while you are on your period. And it is safe for girls to use tampons during their first period.

If you have heard anything about menstruation that is confusing or doesn't sound right, ask your doctor or nurse about it—they will likely clarify any misunderstandings you may have.

Frequently Asked Questions

  • How much blood is lost during a period?

    On average, a woman loses 2 to 3 teaspoons of blood during a normal period that lasts four to five days. Women with heavy bleeding and longer periods may lose twice that amount.

  • How many periods does a woman get in a lifetime?

    A woman typically menstruates approximately 450 times in her life. Research shows women menstruate on average for 35 years and have 13 cycles a year.

  • Who is Aunt Flo?

    Aunt Flo is a euphemism for a menstrual period. Years ago, talking about menstruation in mixed company was taboo. Women came up with other words and phrases for a period, such as a monthly visitor or a visit from Aunt Flo.

    On the internet, Aunt Flo is often shortened to AF. However, AF also has other meanings online, such as alcohol-free.

    Other euphemisms for menstruation include:

    • Carrie (from the movie of the same name)
    • Crime scene or CSI
    • Crimson tide
    • Moon time
    • Mother nature's gift
    • On the rag
    • Rag week
    • Red wedding
    • Riding the cotton pony
    • Shark week
    • That time of the month
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Hightower M. Effects of exercise participation on menstrual pain and symptoms. Women Health. 1997;26(4):15-27. doi:10.1300/J013v26n04_02

  2. Planned Parenthood. Can I have sex during my period? Can I get pregnant during my period?

  3. American College of Obstetricians and Gynecologists. Your First Period (Especially for Teens).

  4. Yang Z, Schank JC. Women do not synchronize their menstrual cycles. Hum Nat. 2006;17(4):433-47. doi:10.1007/s12110-006-1005-z

  5. Centers for Disease Control and Prevention. Heavy menstrual bleeding.

  6. Chavez-MacGregor M, van Gils CH, van der Schouw YT, Monninkhof E, van Noord PA, Peeters PH. Lifetime cumulative number of menstrual cycles and serum sex hormone levels in postmenopausal women. Breast Cancer Res Treat. 2008;108(1):101-12. doi:10.1007/s10549-007-9574-z

Additional Reading

By Tracee Cornforth
Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues.