You've never met a woman who blames their emotional state/response on menstruation!?
Uh, yeah they do. I've lost count how many times I have heard menstruation used as an excuse, regardless of where the woman is in relation to her time of the month. Fortunately my wife does not do this.
I never heard this excuse from women. I hear it from men who want to blame what they perceive as irrational emotional outbursts on a woman's menstrual cycle. You're both unconsciously acknowledging the commonly accepted masculine notion that women cannot be otherwise than rational without being somehow affected by their feminine lady parts. In most cases it's men imposing this view on to women; in others, it's men claiming that women use this excuse all the time. Neither view is accurate.
The women I am familiar with do not participate in this excuse, nor do they appreciate it. But according to TB, I live in an alternate reality called "the university" that exists separately from "the real world," so it's quite possible that the woman I know have no biology to speak of.