8 Possible Reasons for a Missed Period After Stopping Birth Control

Birth control pills are widely touted as the answer to a pesky irregular menstrual cycle. Once you start taking them, you can usually expect period-like bleeding during those placebo pills each month. But once you stop taking birth control, it can be confusing if you have no period (and a negative pregnancy test). But there are a number of possible explanations for a late period, such as stress, obesity, or a thyroid disorder.

We asked experts to weigh in on how birth control pills can affect your cycle and explain the reasons why you might miss periods once you stop taking the pill.

Causes of a Delayed or Missing Period After Stopping Birth Control

Have you stopped taking birth control but haven't gotten your period yet? It can take several months for your cycle to regulate once you stop hormonal contraception, and this is completely normal. In fact, it's common to experience irregular periods immediately after stopping hormonal birth control like the pill.

In a healthy person, the menstrual cycle regulates pretty quickly—often within three to six cycles of stopping birth control; however, bear in mind that hormonal side effects may take longer to clear out of the system. It might take several months for your menstrual cycle to return to normal.

That said, if your period is absent for longer than a few months, there might be another issue at play. Below, you can find the most common things that can cause an irregular cycle after birth control.

Stress

Small daily stressors like missing the bus or getting the kids to school late shouldn't wreak havoc on your cycle. But if you're experiencing significant stress from major life events, or you're finding yourself stressed out of your mind from your daily grind, your cycles may become less regular over time. That's because stress can affect your hormone balance, which plays a crucial role in maintaining a regular menstrual cycle.

Low body weight

Dramatic weight gain or loss, regardless of your starting body mass index (BMI), can impact your cycle. But if your BMI is less than 18, you may experience what's called secondary amenorrhea. That's when your period, which started normally during adolescence, stops altogether. If you suspect secondary amenorrhea, check in with a health care provider.

Obesity

On the flip side, having a BMI of 35 or higher is linked to a host of medical issues, including diabetes, heart disease, and of course, menstrual irregularities. Studies have found a high correlation between obesity and missed periods. Similar to having very little body fat, having a high level of adipose tissue in the body causes disruptions in normal hormone levels like insulin and sex hormone-binding globulin.

Polycystic ovary syndrome (PCOS)

One of the most common causes of irregular cycles is polycystic ovary syndrome (PCOS), which is caused by increased levels of the hormone androgen. While PCOS is not a curable condition, there are treatments that can help regulate your menstrual cycle and increase your chance of successfully getting pregnant with PCOS if that's your goal.

Uterine polyps and fibroids

If you're experiencing irregular cycles or spotting along with symptoms like discomfort during sex and lower back pain, it's possible the root cause of your missed period is uterine polyps or fibroids. Both sound scary, but they're actually pretty harmless.

Polyps are small overgrowths in the lining of your uterus called the endometrium. Typically symptomless, they can cause disruptions to your monthly cycle and spotting between periods. Fibroids are growths found in or on the uterus that can cause painful, heavy periods.

Why can polyps and fibroids cause you to miss your period? Because both occur in response to fluctuations in hormones that also regulate your cycle.

Thyroid imbalance

Who knew your thyroid played such a huge role in your menstrual cycle? It seems strange, but it's true. Your thyroid hormones directly impact your periods, and too much or too little (as in the cases of hyperthyroidism and hypothyroidism, respectively) can cause your cycles to become irregular or stop altogether.

Pregnancy

If you have stopped taking birth control and haven't gotten your period, you could be pregnant. Take a pregnancy test to rule out this possibility if you've had penis-in-vagina sex or engaged in any sexual activity that introduced semen in or around your vagina.

It's possible to conceive after stopping birth control even if your menstrual cycle hasn't returned to normal yet—and no hormonal birth control method is 100% effective.

Breastfeeding

Still waiting for your period to return after birth? Breastfeeding might be a factor. Numerous studies have shown that exclusive breastfeeding commonly leads to a few months of amenorrhea (not having a period) immediately following birth. But there's no definitive guidance on how long that lasts, and often, there aren't any indications that your cycle is gearing up again. This can lead to an unplanned pregnancy if no other method of birth control is used in the meantime.

To prevent pregnancy while breastfeeding, many people turn to the "mini pill," which is a progesterone-only birth control pill. According to Dr. Robbins, "A progesterone-only oral contraceptive pill is excellent for parents who are breastfeeding because progesterone pills do not interfere with milk supply."

Once your period does return after giving birth, it's not unusual for it to be a bit irregular if you're still nursing. But if your baby has been weaned for months and your period still hasn't regulated, it's worth a trip to your doctor to have your hormone levels checked.

How Birth Control Affects Your Menstrual Cycle

When your period returns after stopping birth control depends largely on the reason you went on birth control in the first place, along with any other underlying health issues that were masked by the pills or developed while using them, says Tsao-Lin E. Moy, LAc, a fertility specialist at Integrative Healing Arts in New York City.

If you had an underlying medical condition that was causing irregular cycles—like PCOS, hypothyroidism, or endometriosis—you might notice those conditions rearing their ugly heads again as soon as you stop taking birth control.

"Using a hormonal method of birth control to regulate irregular periods doesn't solve an underlying hormonal imbalance," says Camaryn Chrisman Robbins, MD, an OB-GYN with Washington University Women & Infants Center. "But it can lead to improved quality of life. When someone stops using hormonal medication, it is likely those original symptoms will resume."

Moy agrees, saying that the underlying condition or root cause is still present and will express itself when the person goes off birth control. Sum this up to say that if you're missing your period after getting off birth control, there is a reason behind it—you just have to find it.