On my PMS (premenstrual syndrome : set of symptoms that occur the few days before a period due to hormonal changes) I always get these cramps whenever I'm turned on, it's like I start thinking of something or reading something, the arousal goes up but instead of reaching a peak as usual, I get hit by this sudden pain similar to any regular period cramp, then the arousal goes down.

I never had the opportunity to ask other females about that (except one indirectly), not exactly the kinda thing...