The period is a time of the month when women commune with the devil. It's what the bible says, and it has never steered me wrong.
supposedly hormones in the air. I remember at my old group home, around the same time everyone would be screaming at each other, then a week later the tampons would disappear.
When I was living at home, if I skipped some bcp's to have my period early(no one wants a period while camping), my mom would also get hers early. Unfortunately, she also knew about the "cycle sync" thing and knew who to blame
pheremones I watched a show on tv about it- I don't know what it was called or anything- and yeah I don't know the reason why they would synch in the first place though...
I don't know why it is, but my sister and I are usually synced (and we do live in the same house together). For a while we weren't, but since I've gotten back on the pill we're synchronized again! Woot! I love it. Not my period, just having somebody to eympathize with me.