I've had cyst problems for a long time, usually they come and go, but I always know when I get one because it will hurt really bad on one side, almost always my right. I had exactly what you have a few years ago. I had a cyst that just didn't go away, and it was pretty obvious on the ultrasound that it was getting bigger. My doctor went in laproscopically and removed the cyst and while she was in there removed the endometriosis I had too. The surgery took about an hour, and I was able to go home that day. All I had was a tiny little scar in my belly button. I was sore for a few days, but I felt so much better without that cyst! I still get them from time to time, but nothing horrible. Good luck to you!