Oh this thread hits so close to home. I think I was 16 at the time (I'm 26 now), so it was my 2nd year studying martial arts, I was maybe a green belt or so? That part is fuzzy and irrelevant to the story.
So every Wednesday was sparring and as is the case in most martial arts school, as a female I was in the minority and was very used to fighting the boys. I was fighting this rough yellow belt who really didn't know how to pull his kicks or punches, so if you got hit by him, it was HARD. So he kicked me RIGHT in the groin, exact spot where the cramps pains like to be. So not in the actual lady area, but RIGHT directly above it in those muscles. It was a front kick, toes curled back, felt the whole ball of the foot go right in there. Started slowing down since I was in a *lot* of pain and backing up from him a little, but hands still up, and my sensei sees this, doesn't realize I'm in pain, and yells at me "keep going!" and back then I was pretty darn brainwashed by his tough love attitude at the school, so I was obedient as could be and kept going. I had tears running down my face it hurt so bad.
But this is why I always tell girls that although we don't have to wear cups, it can hurt just as darn bad too