8 Reasons Your Period Is Lighter Than Usual

Admit it: You’ve watched at least one episode of the TLC series, I Didn’t Know I Was Pregnant, and you probably thought the women were crazy. How could someone grow a baby for 9 months and not have a clue?

While we can’t explain why they didn’t notice that their bellies were getting rounder, some about-to-be-moms remain in the dark for pretty long simply because they’ve been taught that as long as they’re getting periods, there’s no way they could be pregnant. Turns out, that’s wrong. (Here are 6 more things women wish they’d learned in sex ed.)

Although most women stop getting periods once they conceive, some continue to experience bleeding, says fertility expert Janet Choi, MD, medical director at CCRM in New York. In fact, she’s had patients who’ve been struggling to get pregnant go out drinking after a light version of their period shows up—only to later learn that they really are with child. 

Unusually light periods or spotting could also indicate an ectopic pregnancy (when an egg implants somewhere other than the uterus), which can be very dangerous. When in doubt, take a pregnancy test.

Late period? There are many reasons for that other than pregnancy. Here are 7: