Sex and your menstrual cycle: Are they connected?

If you’ve recently become sexually active, it’s normal — and a great thing — to be full of questions about how it might impact your body. So if you’re wondering if sex could be affecting your monthly cycle, you’re certainly not the first. Keep reading to find out how sex and other common factors can impact your period.

Key takeaways

• Your menstrual cycle is controlled by hormones, which aren’t affected by having sex.
• Sex can result in pregnancy, causing your periods to stop, or a sexually transmitted infection, which can cause irregular bleeding.
• Having sex can sometimes help to relieve period cramps.
• If you’ve noticed changes to your periods, know that many different factors besides sex could be behind this, from stress to breastfeeding.

Does sex affect your menstrual cycle?

So, does having sex affect your cycle? The short answer is no, not really, according to our Flo expert. “The menstrual cycle is how your hormones fluctuate at certain times of the month, which eventually leads to a period, and sex doesn’t alter that normal hormone fluctuation,” says Dr. Charlsie Celestine, obstetrician and gynecologist, New Jersey, US. 

Ready for a quick science lesson? Let’s take a look at those hormonal fluctuations more closely. 

In the first phase of your cycle, the hormone estrogen rises, which causes the lining of your uterus to thicken. Meanwhile, follicle-stimulating hormone causes your ovaries to develop a fully mature egg. Next, luteinizing hormone causes ovulation (the moment that an egg is released so that it is free to be fertilized by a potential sperm). 

In the second phase of your cycle, the hormone progesterone rises to help prepare your uterus for pregnancy. If you don’t get pregnant, estrogen and progesterone drop, causing your body to start shedding the lining of your uterus (your period). 

However, while sex in general won’t impact these hormonal changes, a few studies have looked into whether having regular sex might indirectly impact your cycle. Interestingly, these suggest that having regular sex (which the researchers defined as at least once a week) can make your periods more predictable. According to one of these studies, this is because not having regular sex might increase stress, which is known to interfere with ovulation and cause irregular cycles. More research is needed to confirm these findings, but it can be fascinating to think there could be a link. 

Not sure when your next period is due? Tracking your cycle with an app like Flo can help you get to know your body better, or you can use our handy period calculator. 

Can sex delay periods?

You may also be wondering whether sex can throw off your period. Well, having sex will not delay your period, but if it leads to pregnancy, then your period won’t show up. We’ll explore this in more detail below. 

Does having sex affect your period pain?

If you’re up for period sex, the good news is that female orgasms can help ease period pain for some women and people who have periods.  

“An orgasm can help with period pain,” Dr. Celestine explains. “That’s because dopamine released in the brain during orgasm acts as a natural painkiller. Also, the stress relief from endorphins helps.” 

Why might your period start after having sex?

Ever found that having sex seems to hasten the arrival of your period? “Usually this happens if you are close to a period,” says Dr. Celestine. “So if a period is just ending or about to start, then the act of having sex, which somewhat shakes the uterus, might cause bleeding to start a little earlier or last a little longer. This is because it loosens up, so to speak, the lining of your uterus that’s close to shedding, and it comes out.”

Factors that might impact your menstrual cycle

If you’ve noticed a change in your cycle, it could be related to one of these factors. 

Pregnancy

If your period is late, it might mean that you are pregnant. A missed period is one of the earliest signs of pregnancy. If you get pregnant, the fertilized egg implants into your uterine lining, where it can continue to develop into a baby. When you don’t get pregnant, you shed the lining of your uterus, and menstruation (your period) starts. If you want to avoid pregnancy, make sure you use either hormonal or nonhormonal contraception, even if it’s your first time having sex. 

Hormonal birth control

Hormonal methods of birth control change the body’s natural hormone levels to prevent ovulation. Examples of hormonal birth control include the contraceptive pill, the implant (which a doctor inserts in your arm), and a hormonal intrauterine device (IUD), which a doctor inserts into your uterus. 

There can also be changes to the actual bleeding itself, depending on what kind of hormonal contraception you’re taking. For example, traditionally, you take the pill in a 28-day cycle that includes a seven-day break when you’ll have a bleed. Some women and people who have periods also notice light bleeding or spotting throughout their cycle during the first few months of taking the pill. 

Menopause

Menopause is when you stop having periods. It happens when the ovaries stop making the hormone estrogen. Your doctor will confirm that you’ve been through menopause once you haven’t had a period for a whole year. On average, this happens around age 51. 

This might sound daunting, but the changes are usually gradual. The transition to menopause is known as perimenopause, which can begin in your 30s or 40s. A common sign of perimenopause is often a change in your cycle, which may become longer or shorter, or unusually light or heavy. That’s caused by normal fluctuations in estrogen as you age. 

Stress

Stress is another factor that can mess with your period, all because of the stress hormone cortisol. It can make periods lighter, delayed, or temporarily disappear. It all depends on how your body manages stress. The things that trigger stress are also personal, with the same circumstances — whether that’s moving to a new house or navigating a busy job — impacting different people in different ways. 

STIs

The common sexually transmitted infections (STIs) chlamydia and gonorrhea can sometimes cause bleeding between periods. When left untreated, the infections can spread to the uterus, tubes, and ovaries and become another condition called pelvic inflammatory disease (PID). Irregular bleeding is also a symptom of PID. 

Getting symptoms like these can be worrying, but try not to panic, as abnormal bleeding can also sometimes be harmless. The important thing is to speak to your doctor as soon as you can. They may recommend that you take an STI test. Keeping up with your regular sexual health screenings will also greatly reduce these risks and can help bring you peace of mind.  

Even if you do have chlamydia and gonorrhea, rest assured. They can be treated and are definitely nothing to be ashamed of. And if you’re worried about catching an STI in the future, know that condoms provide the best protection. 

How does your menstrual cycle affect your sex drive? 

So now that we know how sex impacts your cycle, let’s look at how your cycle can impact your sex drive. “As your hormones change during the menstrual cycle, your desire for sex changes,” says Dr. Celestine. “Usually midway through your cycle, close to ovulation, when your estrogen levels are higher, you desire sex more. And closer to when your period is starting, progesterone is the dominant hormone and can make you desire sex less. This is not the case for everyone but is common.”