I realized that women have very limited empathy towards other women, when it come to menstruation. This is a bit counterintuitive because you'd expect them to be full of empathy, seeing as they know exactly how it feels. And, in fact, that is the first emotion than always arises between two understanding women in a situation when one of them has her period. This empathy however is rather limited because, despite the fact that women have experienced more or less the same thing and know what it is like, they have also experienced on a regular basis, having to go through day-to-day tasks while having their period. So basically, women do feel a sort of sympathy for each-other, but they also feel that others should be able to go through what they go through.
Thank God for that, I suppose, because other wise, all women would do is go to little sympathy groups and never get anything done.