11 Reasons You Missed Your Period (Other Than Being Pregnant)

The experience of having a late or missed period can be pretty stressful, particularly if you're sexually active but aren't exactly ready or want to get pregnant at the moment. You start to count your birth control pills, or if you're not on contraceptives, you obsessively look through your calendar. Then, you might decide to go down the rabbit hole of googling why your period could be late, and well, we all know that looking up symptoms online can be mildly alarming at times and normally does nothing to reduce any fear or anxiety. The stress is real, and there's science that shows the worry can cause your period to be even more delayed.

But there are actually a lot of other reasons for a late or missed period besides pregnancy. Yes, your body works in mysterious ways sometimes.

If you're reading this and going "Uh huh, been there," I did us both a solid and reached out to an actual professional, not Quora or Google, to get their take on the causes for a missed period. Here's what Navya Mysore, MD, a family provider at One Medical, had to say.

First, don't stress too much. And I know that's easier said than done when you're not quite sure what's going on with your body. "There are a number of reasons why you can miss your period, aside from pregnancy," Mysore says. "Some of these reasons can be normal changes that happen in life, and others can be the body's reaction to external triggers."

If you're sexually active and miss your period, Mysore says you should take a pregnancy test to ensure you're not pregnant. The Cleveland Clinic says you should wait five to 10 days after your period is late to take a test.

"If your pregnancy test is negative, I always suggest reviewing your symptoms and missed period with your primary care provider or gynecologist," Mysore explains. "It's important to figure out the reason why it's late or skipped one month. It might be totally fine to wait and see what happens with time, but it's always a good idea to review that decision with your doctor first." This idea is the same even if you aren't sexually active but missed your period.

Stress REALLY messes with your whole body. "Stress can cause a hormonal imbalance and throw off the regulation of your hypothalamus, a part of your brain that is in charge of regulating your period," Mysore says.

Again, it's tough to keep your stress in check, and simply telling yourself not to stress out might cause you to freak out even more or might not help at all. Find some self-care or mental health strategies that can help relieve anxiety or worry. That might be talking to someone, writing down your thoughts, or even taking a nice bath.

"General low body weight can throw off your period, as there is less leptin, which is a hormone that is triggered by your percentage body fat and helps regulate your estrogen levels," Mysore explains. "Eating disorders or intense exercise can be reasons for a low body weight."

PCOS can be another reason for irregular or missed periods. "It's a condition that causes your body to produce more of the male hormone androgen," Mysore explains. "Cysts can form on your ovaries as a result of this hormone imbalance, making ovulation irregular or stopping it altogether, which in hand can make your periods irregular."

Yes, sometimes there is such a thing as exercising too much. If you're hitting the gym too hard, you could have low body weight, which we already mentioned can contribute to a missed period. Texas A&M Health also says that excessive exercising could lead to lower estrogen and that some athletes might experience secondary amenorrhea (no period for six months or longer).

Texas A&M Health also says that extreme changes in sleep patterns or your circadian rhythm (like coming off night shifts at work or dealing with jet lag) can confuse your menstrual cycle.

"An underactive or overactive thyroid gland can also throw off your estrogen and progesterone levels, which can cause irregular periods," Mysore adds. Your doctor can test for this during a visit.

"When starting a new form of birth control, you can initially have an irregular period, and in fact, some forms of birth control may cause you to lose your blood from your period altogether (progesterone-only IUDs)," Mysore explains. "When going off birth control, you can find yourself in the same position, where you may not get your period for some time, even a few months before your natural period comes back into play."

Irregular periods can be a side effect of some medications, Texas A&M Health says. Before you start a new medication, make sure to discuss with your doctor the side effects. And if you are on a medication that may cause irregular periods, you should also discuss the potential effects on your cycle. 

According to the Office on Women's Health (part of the U.S. Department of Health and Human Services), some women might not get their periods back until after they stop breastfeeding. Some might ovulate without realizing it while their baby transitions from breastfeeding. The office suggests that women who are nursing discuss their birth control options with their doctor if they don't want to get pregnant right now.

"Perimenopause, which is a normal transition for women, can cause irregular periods due to a normal shift of your hormones, estrogen and progesterone," Mysore says. It happens before menopause, and according to Harvard Health Publishing, on average, it can last three to four years, but in some cases, it can be a few months to as long as a decade. Some other symptoms include hot flashes and night sweats, vaginal dryness, uterine bleeding problems, sleep disturbances, and mood symptoms.

In some cases, a missed period can be a sign of a serious health problem, like birth defects or tumors in the brain. According to the Office on Women's Health, "Once these problems are treated, your period may start for the first time or you may get your period again if it had stopped."

Next up: The Supplements That Can Help Your PCOS Symptoms, According to an Expert