If you happened to open Walgreens Facebook page and play their "Instant Win" quiz, you'd be posed with a real chin-scratcher: "You can have sex on your period. True or false?"
If you answered, false, congratulations, you're just as grossly misled as Walgreens is.
A woman's vagina does not grow teeth during her period, nor will it be guarded by barbed wire that will permanently injure your penis upon entry. Now stop surfing the web for Allison Brie GIFs, and enroll in a sex-ed class. Your future partners will thank us.