There's nothing like the strong bond that's created when two women find out their periods are almost synchronized, or when they officially become period sisters, to be exact.
But according to the video by DNEWS above, the theory that best friends or two women living or working together end up having the same period cycle may be nothing more than a myth. Now, while studies since the '70s have suggested this synchronization may be possible with roommates or lesbian couples, more evidence shows there are many other factors that can change the cycle of menstruation.
Things like stress, diet and even certain medications like anti-depressants can lead to irregular periods, which can seem like you're matching up with your best gal pal, DNEWS points out. So chances are, it's likely a coincidence your cycles are matching — which pretty much suggests you're soulmates anyway.
Other period myths people have believed (or still believe) include everything from the fear of tampons floating away inside your body to the notion that swimming while on your period can attract sharks.
But there is a lot more science behind why your period may be irregular. Watch the video above to find out.
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