Cramps and pain during sex

I’ve been dealing with painful cramps that happen all month, they seem to get worse when I have to pee. I also suffer from painful sex, doesn’t matter the position, of course deeper penetration is worse but I still have pain without deep penetration. But my doctor has no answer for me as to why, I had an ultrasound and there was nothing abnormal and she’s just dismissed it since then. Has anyone else experienced this and had a normal ultrasound? Because it’s so annoying being in pain every time I have sex and having to deal with these painful cramps.