I've never seen or heard anything like this. In fact I've been in a few HC raiding guilds that didn't give a crap what gender you are as long as you are pro and reliable. I have however also raided with a lot of other female's over the years that are just plain bad or attention whores. So I can see where they're coming from. My personal rule is to not talk in vent till after the first raid with new people, that way the can judge me as a player before they find out I ovulate. It tends to solve that issue quite well.