Stephanie Hallett
June 14, 2017 7:36 am

If your menstrual cycle is pretty regular, having a period come early can prompt small (and sometimes large!) bouts of anxiety. Questions arise like: Did I take my birth control? Am I pregnant? Did I break something?! It’s stressful.

And since we know it can be unnerving to have your body behave in unexpected ways — especially when it comes to your reproductive system — we spoke to Dr. Jennifer Wider, a women’s health expert, to find out why your period may have come early. She explains to HelloGiggles that lifestyle changes, diet, illness, and even stress can affect when your period arrives.

Read on for six reasons your period showed up unannounced.

1You’re dieting.

If you’ve changed up your eating habits or you’re trying to lose weight, the frequency and regularity of your period can be impacted. Dr. Wider says that if you’ve lost too much weight, you may lose your period altogether, but weight loss can also cause your period to come early.

2You’re taking medication.

Anyone who’s been taking the birth control pill for a while knows that if you miss a dose or two, your period will come early. Dr. Wider notes that blood thinners can also cause women to have an early period.

3You’re stressed.

Says Dr. Wider, “Mental stress can cause fluctuations in our hormones, which can affect a woman’s cycle.” So if work or school is making you crazy, don’t be surprised to see Aunt Flo sooner than expected.

4You recently took the morning-after pill.

This won’t be true in every morning-after pill case, but Dr. Wider explains that “if you take the morning after pill three or more days before you are due to ovulate, chances are, your period will come earlier.”

5You have an undiagnosed condition or illness.

According to Dr. Wider, “endometriosis, thyroid conditions, PCOS (polycystic ovary syndrome), and other conditions that can interfere with the hormones in your body” can all cause your period to arrive early. Speak to your doctor if you feel you need to find out if you’re living with any of these.

6You’re approaching menopause.

If you’re in your late 40s and in the perimenopausal phase, you may notice that your periods are becoming less predictable, much like they were when you were just beginning to menstruate. Approaching menopause can definitely cause you period to come early.

At the end of the day, every body is different. If you notice any drastic changes in your menstrual cycle and you’re not sure what’s going on, your best bet is to speak to your doctor immediately. They’ll be able to point you in the right direction.