It’s also that even time off can be difficult to get, because of a lack of acknowledgement of variability in menstruation. I have seen way too many situations where a manager (or whoever is responsible for okaying time off) underestimates how bad it can be for some people, possibly because no-on close to them has bad periods, so they think that everyone who struggles is playing it up for time off work.

Something that really icks me out is that there have been a few times where I have been used as a comparator to shame colleagues; I have always been blessed with light and pain free periods, and when I was on hormonal contraception, they actually stopped entirely. This meant I never needed time off for menstrual reasons, and this was used to sort of say “well Ann presumably menstruates and just gets on with things, so why can’t you?”. Many of us have had the experience of asshole managers who micromanage employee sickness and are exhausting to deal with, but there’s a subset of those who are extra assholish around menstruation related sicknesses. Something I’ve seen once was someone who seemed to be tracking the periods of her employees, and would call up to query times if you had taken period related time off and it didn’t fit into her predictions. I can only assume that she was fortunate to have super regular periods, but many people who do suffer enough to need time off work can’t predict their periods to that degree of accuracy.

But as others have said, it’s not just about time off, but sometimes it’s small stuff like taking additional or longer bathroom breaks. Or, when someone has come back from a menstruation related sick day, jokes like “you feeling better? Great, just make sure you don’t bleed on the chair, haha”, to the entire office. Obviously that’s inappropriate and the kind of thing you’d report to HR, but it’d be less prevalent if people were less weird about menstruation in general.

In a way, I appreciate your being confused by this, because if more managers thought about this like you do, this wouldn’t be nearly as big of an issue. But way too many people make it weird.