I’m not sure if it’s really a thing. From what I understand there’s never been anything to scientifically prove it happens.
But statistically it’s quite likely that you’d get similar periods at times to your friends. If you went for a cycle length of 30 days (because it’s an easy number 😂) there’s a 1 in 30 chance you’d start the same day. If your period lasted for 3 days, that’s about 1 in 10 that you’d be on your period at the same time for at least a day
Adding that everyone’s periods/cycles are different lengths (so can fluctuate when they happen each month). It’s likely to be on your period with a friend for one of those days
😂 kinda boring maths. And who knows there might be some hormone synchronisation that might happen over enough time living together
