Endometriosis possibility

So I've had lots of trouble lately with period-like symptoms, it started a week ago and the pain caused me to miss an important meeting. I went in today for an ultrasound of my ovaries (I'm prone to cysts) and appendix but they came back normal. My doctor thinks it could be endometriosis. My colon is fine, my ovaries and appendix are fine, and I don't have any gastrointestinal issues. Anyone have any suggestions what I can do to ease the pain before I know for sure what's going on? OTC pain meds don't help at all