6 reasons your period came early, according to a doctor

If your menstrual cycle is pretty regular, having a period come early can prompt small (and sometimes large!) bouts of anxiety. Questions arise: Did I take my birth control? Am I pregnant? Did I break something?! Ultimately, why did my period come early? It’s stressful to look at that trusty period tracker app and realize that Aunt Flo decided to come 4 days, 10 days, even a week or two ahead of schedule.

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. So before you freak out about what could possibly be wrong with you and your uterus, be mindful that an early period can stem from a number of factors, and some are no big deal. Also remember that you know your body and your cycle best, and knowing how your body feels at different stages throughout the month can better inform you of what to look out for when your period is coming, so you can be prepared if it does happen to come early.


Here are a few possible reasons why your period came early:

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. That’s because the hormones estrogen, progesterone, and testosterone, which regulate the timing of your period, can be affected by what you eat. 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 as can medications like antidepressants, blood pressure pills, and even antibiotics.

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 your 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.

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