Painful sex

So on occasions when me and my other half have sex it's really painful! Mostly afterwards but sometimes during aswell. I'll lay there for anywhere up to an hour with severe pains that honestly feel worse then labour pains and then for the next couple of days will get mold cramping. I have been to a few doctors, had tests and ultrasounds done and they keep telling me there is nothing there! How is this normal. Has anyone else had this?!!

It's so annoying and painful. I want to enjoy sex but honestly some times I'm scared of it!