cottage cheese

I feel like Boojum said everything that needed to be said in his comment. The level of education about sexual reproductive organs and menstrual cycles and generally anything involving genitalia in many first-world countries is strikingly poor.

You should really google female anatomy, and be single for a while as you work on improving yourself. The chances are, the girl in question is really cut up about your reaction to her natural bodily functions and her percieved lack of cleanliness from your point of view.

While the ship may have sailed on getting her back, you should at least find it within yourself to apologise for your overreaction as she is almost certainly as embarrassed about it as you are, if not more.

Taking that last paragraph into account, if you're not going to apologise from a place of genuine remorse, and the reminder of going down on her when you next see her face will cause you to vomit in your mouth a little, a fake apology will arguably make her feel even worse so in this case don't say anything and move on.

There's a difference between what is right and what is easy.