What could be wrong with me?!

So I’ve noticed this pain that has been happening for some time now during orgasm only. I am a virgin and only masturbate using clitoral stimulation. During orgasm I experienced this intense stab through my pelvis area that is usually followed by blood no more than 15 minutes later (almost period amount of blood only lasting 4 hrs). The initial pain is a enough for me to double over and I cannot move, for about 30 seconds, until it stops. I’ve been to my OB and she recommended me to have an ultrasound which didn’t help me figure anything out except that my uterus is heart shaped. She had me change my BC to the pill instead of the ring and before that I had a IDU which I can no longer her have dude to the shape of my uterus. I’ve never experienced this type pain before in my life until about 1 1/2 yrs ago when it started. It didn’t use to happen every time but now it is. What do you think could be wrong? I’m very concerned.