While it's common to feel tired during your period — and you may not want to exercise, as a result — you definitely don't need to wait for it to be over before working out. In fact, the more you move, the more oxygen flows through your body and decreases prostaglandin release, which can help alleviate cramping, Dr. Jessica Shepherd, OB/GYN and U by Kotex partner, tells Bustle.

"Exercises also trigger the release of endorphins which can induce 'exercise euphoria', an altered pain perception which can help women with menstrual pain and cramps," Shepherd says. "But, you should also listen to your body and do what feels right. If you’re tired and don’t have the energy, listen to your body and take a rest day."

Have you ever heard the myth that your period stops in water, or that it doesn't flow if you're swimming or taking a bath? Well, it isn't entirely true.

"While it may seem that swimming on your period may slow down menstrual flow (and it sometimes even stops) in the water, that isn’t what happens," Shepherd says. But there are a few reasons why that may seem to be the case.

"The counter pressure of water might stop a menstrual flow from entering water," Shepherd says. "Additionally, if you are floating or swimming, the lack of gravity can hinder a menstrual flow from coming outside the vagina."

That said, you'll still want to follow your usual routine. For example, if you use tampons, you should change them as frequently as you would when staying dry, Shepherd says, which is at least every four hours.

While there's a belief floating around out there that you can't get pregnant if you have sex during your period, the reality is it's still a possibility.

If you have a shorter than normal cycle (less than the typical 28 days) or if your period is lighter than normal, you might ovulate sooner than expected and get pregnant, Dr. Monique May, a board-certified family physician with over 20 years of experience, tells Bustle.

"Also, sperm can live up to three to five days inside of the vagina, so depending on how close to ovulation you have sex, pregnancy is possible," May says. So if you want to have sex during your period, go for it. Just be sure to continue using your usual form of birth control.

If you want to have sex during your period, you very much can — despite what the myths might say. In fact, many people "love to have period sex since there is more blood flow to the pelvis, including the clitoris," Ross says.

It can also be a great time to try new things, like having sex in the shower, or to use your period to your advantage. As Ross says, "Couples who enjoy sex during a period find the menstrual blood acts as the perfect lubricant."

Another myth, May says, circles around the idea that you need to clean out your vagina or use a douche post-period, in order to get rid of extra blood. But this is false.

"Douching is not only not needed but is actually harmful," May says. "Douching removes the normal bacteria that live in the vagina and allows the overgrowth of bacteria that cause a [...] vaginal discharge called bacterial vaginosis." And that can lead to more serious health issues, such as pelvic infections.

"After your period the body naturally eliminates any residual menstrual blood," May says. So don't feel as if you need to help the process along by using a douche, and potentially disrupting your body's natural bacteria.

Many people poop a lot during their period, so it can feel like this is something that's 100% guaranteed to happen. But the truth of the matter is bowel changes will be different for everyone, Shepherd says. Some people will poop more during their periods, and some will experience constipation.

If you do poop a lot, there's a reason why. "When the estrogen and progesterone hormones dip a few days before your period starts, they're replaced by prostaglandins," Shepherd says, "which are chemicals that are released during your cycle to give your uterus and intestines leeway to contract."

"Some believe having period sex makes your periods shorter since the uterus pushes out the blood faster making periods shorter," Ross says. But in reality, having sex during your period will have no effect on the length or flow of bleeding. It won't cut your period short, hurry it along, or make your flow light. So this shouldn't be a factor worth considering.

"Unfortunately this is completely untrue," Ross says. "In fact, women are more prone to contracting STIs when having unprotected sex during a period since the blood acts as a petri dish for hungry organisms." Meaning bacteria and viruses may be more like to spread. To keep yourself safe, you'll still want to use a condom and follow your usual safe-sex practices, even if you have your period.

Some cramping during your period is typical, and is usually nothing to worry about. Painful and debilitating cramps, on the other hand, aren't something you need to deal with.

"It is not normal to have menstrual pain so severe that it interferes with your daily life," Dr. Kenneth Ward, board-certified obstetrician/gynecologist, tells Bustle. "If it gets to that stage, there is usually something else going on," including conditions that make period pan worse, like endometriosis.

If your period pain is so intense that it's holding you back from going to work or school, Ward says, you'll want to reach out to a doctor for an evaluation.

After all, your health is the number one reason why it's important to question these period-related myths, and find out whether or not they're true.