The hormone progesterone peaks right before your period, which may have an effect on how things move through your intestines, OB-GYN Alyssa Dweck, MD, co-author of V Is for Vagina tells BuzzFeed Life. “So some people will have alternating constipation or diarrhea or just a general feeling of discomfort or gastrointestinal stress.”

One study found a relationship between period poop changes and prostaglandins, the hormone-like compounds that can trigger cramps. They found higher concentrations in people who had diarrhea during their periods, so that might explain why you’re looser than normal while other people complain about not pooping since Tuesday.

And those period farts? Those can come from your hormones too. Your gut bacteria actually changes along with your cycle, since it's affected by your fluctuating hormone levels. As the bacterial fermentation changes, your gas changes — even if your diet stays the same, says Chutkan. So that's why it smells like you just housed some Indian food, even though you did no such thing.