I too have Ovarian Remnant Syndrome. I have already had one surgery to try to remove my remnant, but it was unsuccessful. When I had my FSH levels done, it showed that I had the normal levels of hormones for someone who has normal functioning ovaries. I would recommend that you have your doctor do an FSH blood test. This will help your doctor know how functioning the ovary is. When you ovary was removed, was it adheared to any other organs? If so, that could be why you have ORS. When they "peel" the ovary from other organs, small cells get left behind. Even the smallest piece of ovarian tissue can function and grow cysts. It is very trick to get all of the remnant out due to the fact that there could be microscopic cells left behind. Seeing a gyn/onc is a great idea. Please keep us posted on how you are doing. If you ever need to talk, private message me. ORS can be a very lonely condition. Many doctors do not believe in it.
It is somewhat rare, but if some ovarian tissue was left behind in a prior surgery sometimes it can regrow or behave like a full ovary. Getting at it tends to be trickier because it likely attached itself to something. Not sure what type of doctor you are seeing at present but this requires a top specialist to review for accuracy. If available in your area, please get yourself referred to a gynecologist/oncologist. They are experts at female surgeries and disorders, including benign ones.