Natural female hormones are only high a few days a month, yes. And we're so used to it, we get prepared and tell our partners we'll cry and be angry for no reason, and get ice-cream and chocolate in the house and maybe even take time of work if lucky enough. But it's not for very long, and there is a theory that you only get sad and angry if you have something sad or angry to be about, which I partially agree with. But the physical low is real, regardless of what emotions are going on.
