It sounds like your cyst is simple (fluid filled) which is not how
ovarian cancer shows on a scan. You would likely have a
large (5cm or greater), complex mass (has solid parts).
Cysts can really hurt! They also can persist. Heat was always very helpful for me. Both hot baths and microwave heat packs can get you some pain relief. But, if the pain persists, you should go back to your doctor see if anything has changed. If your cyst has grown or changed, it could account for the pain.