mystery pain

I was awoke from my sleep with a pain in my back and pelvic area that grew worse. I felt I was going to vomit because Ive never had that much pain strike so sudden. I wanted to cry as I rocked tossed and turned. It lasted about 30minutes and just as fast as it came it suddenly went away. By that time I was completely drenched in sweat. I'm afraid it will return at an inconvenient time.