Horrible Cramps after orgasm?

Does anyone have unbearable cramping after an orgasm by clitoral masterbation or right after sex? It seems very rare when I try & research this experience. This happens to me out of no where without warning. I have even scared my boyfriend twice after I hit the floor or get in the tub after sex to calm my pains. My gynecologist has asked me to keep a diary for when I get these pains and how. It's just to random to keep track of. The pain last a good 30 minutes to an hour. I hurry to take pain medication and ride it out in the tub or over the toilet. So at times it's so painful I shout out and cry, I never go to the hospital because it passes. Has anyone experienced this or has any insight, please?