What’s wrong with me?!

So I’ve noticed that has been happening for some time now only during orgasm. I’m a virgin and only masturbate using clitoral stimulation. During orgasm I experience this intense stab though my pelvis area that is usually followed by blood no more than 15 minuets after (almost period like amount only lasting 4 hrs). The initial pain is enough for me to double over and I cannot movie, for about 30 seconds, until it stops. I’ve been to my OB and she recommended me to have a 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 an IUD which I can no longer get due to the shape of my uterus. I’ve never experienced this type of pain before in my life until about 1 1/2 years ago when it stared. It didn’t use to happen every time but now it is. What do you think could be wrong? One very concerned.