To check if you have endro they have to do laproscopic surgery. Basically they put a little camera in through your belly button. It is a very serious disease that gets overlooked most of the time. It is probably worth looking into. Doctors suck sometimes, I will definately agree.
They think I have endo, but I have not had the "surgery" to make sure. Mainly because # 1 I do not have health insurance and # 2 they usually "cut it out" if you have it, and I do not want that done yet. Mainly because, they will usually only cut it out so many times before you have to have a hysterectomy, and I am young and if I do decide I want kids, I want to be able to have them.
Put your foot down and make them run tests. If you have insurance and you complain enough they will have to it. Good luck and I am truly sorry you are going through this.