Possible Causes of a Late Period
(Besides Pregnancy)

One of these conditions might explain your delayed or missing period

After puberty, you should notice that your period starts to come each month with some regularity. While your average cycle might vary by a few days from one month to another, you might notice that it occurs late.

The occasional odd cycle is nothing to be alarmed by, but realizing that this month’s start date somehow managed to fly by with no sign of your period coming can generate some major anxiety.

Taking a pregnancy test is most women’s initial reaction when they have a late period, but a negative test often reveals far more questions than answers. Your period is regulated by a complicated balance of hormones, and there are many completely natural (and harmless) things that can throw it off.

When you find yourself staring at the calendar with anxiety, or taking multiple pregnancy tests that turn out negative, knowing what to do when your periods are late can help you figure out your best course of action.

If you are concerned, don’t hesitate to schedule a check-up with a trusted and compassionate OB/GYN at All About women for answers. In the meantime, here are some of the most common causes of a late period, besides pregnancy.

Hormonal birth control

Many forms of birth control contain the hormones estrogen and progesterone, which are responsible for regulating ovulation and menstruation. It’s common to experience changes in your menstrual cycle when you are first starting or stopping a new form of hormonal contraception.

Usually, this evens out after 1 to 3 months, but you might need to tell your doctor that you’ve had a missed period (but aren’t pregnant) to see if a hormonal imbalance might be the cause.


Stress sends signals to your brain that tell it to focus on creating special hormones such as cortisol to reinforce the fight or flight instinct. A flood of stress hormones can interfere with your reproductive processes.

Chronic stress can also change your sleep patterns, cause you to experience fluctuations in your weight and other effects that can cause your period to stop. Ironically, stressing over a missed period could cause it to disappear for longer.


If you’ve recently had a baby and are breastfeeding, then you can thank hormones again for the odd experience of missing your period. Prolactin is a hormone that your body produces to stimulate breast milk production. It also has the side effect of causing your body to cease menstruation. You might also notice spotting or lighter periods while you are nursing.

Overactive or underactive thyroid

Your thyroid is responsible for helping to regulate your body’s metabolism. If anything goes wrong with it, then it could cause an imbalance in your body’s hormones. Signs of an underactive or overactive thyroid include excessive fatigue, a rapid heartbeat and mood swings. Thyroid disorders are easily diagnosed with a simple blood test and physical exam.

Extreme training and exercise

Reproductive hormones, such as estrogen, require some degree of body fat to perform their functions. Women who are in extreme training programs for sports or recreation may find that they reach a level of low body fat that causes their periods to stop.

Usually, periods resume normal cycles once you stop training more than two hours per day.

Changed sleep habits

Your body needs good rest to maintain its essential functions. Women sometimes find that changes in their sleep patterns are responsible for late periods. For example, perhaps you traveled recently and your body is still recovering from adjusting to a new time zone. Or maybe you started working the night shift.

Major changes in your sleep schedule can throw off your body’s circadian rhythms, which includes making it harder for it to follow a regular menstrual cycle.


Delayed periods can also occur when you are overweight. Being overweight is associated with health conditions such as diabetes and polycystic ovarian syndrome (PCOS) that impact your body’s natural hormone production.

Implementing weight management practices can help to get your cycle back on track, but you may also need testing to make sure that you don’t have an underlying condition that is associated with weight gain.

Perimenopause or menopause

Many women expect their periods to just suddenly stop when they hit menopause. While there are a few lucky women who make it through this transition with very few disruptions, it’s much more common to have irregular and abnormal periods for a while.

Perimenopause occurs during the months or years before menopause, and it usually starts around your mid-forties. However, some women start this stage much earlier, and skipping a period here and there is a sign that it might be happening to you. As with many of the other causes of a late period, a visit to the doctor can help you find out if you are entering this new life stage.

When to talk to your OB/GYN

Since there are so many things that can cause you to miss a period, it’s hard to figure out for sure what is happening to you on your own. If you get a negative pregnancy test and think you could still be pregnant, then wait a few days and test again.

If you know that there’s no way you could be pregnant or you receive a second negative test, then consider reaching out to your OB/GYN. Your doctor can run special tests to check your hormones and other health factors to figure out what you need to regulate your period again.

Schedule a checkup at one of our All About Women offices in Gainesville and Lake City, FL with one of our caring and trusted doctors. We’re ready to answer your questions and get you on the path toward a healthier and happier YOU.