If you thought your period was synced with pretty much everyone on your floor freshman year (because same), get ready to have your world shattered - according to science, period syncing is not a thing.
As Cosmopolitan reports, the results of a study done by researchers at the University of Oxford and fertility app Clue show that period syncing is probably a myth. The research studied 360 pairs of women who were living together, and three of their consecutive menstrual cycles. The findings? 273 of the pairs of women (a huge majority) had greater differences in their period dates on their final cycle than they did on the first one researchers studied.
Translation: menstrual syncing is probably more of a coincidence that we really, really wish were true. Since women's cycle lengths often change even within a single year, it's easy to see how one or two of your periods could have synced up with a roommate or your sis - but they've also probably been out of sync just as much, if not more, than they've been in sync.
"We’ve also done some statistical tests and found that the difference in cycles actually grows," researcher Marija Vlajic told The Guardian. "This doesn’t mean that pairs go out of sync – it means they were never in sync in the first place."
You're also more likely to notice you're synced when you're both dealing with (and commiserating about) Aunt Flo together - after all, nobody complains about not being on her period, am I right? So don't be too bummed - it'll just make the times when you and your bestie can complain to each other about cramps and tampons all the more, erm, wonderful.