Pain after orgasm

I don't know who else to ask so please bear with me. For a couple days I've had some cramping after orgasm but nothing too bad. Well last night was horrible. I couldn't stand up for a good twenty minutes I laid there curled up in a ball crying. I finally got some heat on it and managed to pass out. Today it is still hurting just to walk around. I teach and had to leave before noon because I couldn't keep up with the kids because of the pain. It hurts to stand too long. It hurts like cramping from hell more so on the right side. Any ideas what it could be or how to help? My SO and I are trying to get pregnant and just in case I tested this morning. I was worried something went wrong baby wise but tested negative.