Keep good records of your symptoms - maybe use a period app to do that - and every time you go to the doctor, get it on record that you are having pain, let her (or whatever doctor you see) know how much pain you are
in, what your periods are like, if
sex is
painful, if orgasms are
painful, if bowel movements are painful, etc. The better the documentation, the better the chances of you getting what you want when you want it.
Good luck!