As a man, I have never menstruated. I know of no man that has had a period.
Sex and gender are synonymous. Now, “gender roles” are a different thing, but to say sex is different than gender is disingenuous, if not totally incorrect.
I wish I could make the claim that I came up with the notion that men don’t have periods, but biology beat me to it.
If people want to chop off body parts, or pretend to be something they aren’t they are within their right to do so. My issue is with making it seem “normal” and thus confusing children into thinking that just because a girl likes to play sports means that “oh, maybe I’m supposed to be a boy”.