I think this is a cultural response to sex in general as well as a cultural response to weakness. A Chinese friend turned down a coffee date by saying, "I'm menstruating this week, but I'm free next week." That was shocking to me, raised by an old-school father who couldn't even say menstruation. American sexual taboos are so strong that anything happening in women's nethers are unmentionable.
By comparison, my grandfather once said, "my side hurts". Turned out two weeks earlier he'd been rammed up against a fence by a bull, breaking two ribs, yet he told no one. It isn't so much a man v woman thing but a larger discussion on cultural embarrassment.