Did you obtain a copy of the ultrasound report? It can help to review that and have a basic understanding of its contents when you talk to the ob/gyn. And you can share that here if you'd like. Hopefully, the report was forwarded to the ob/gyn.
Oftentimes, cysts just need to be monitored via periodic ultrasounds since most resolve on their own, no intervention needed. You don't want to undergo surgery unless it's necessary. If the cyst continues to grow and has to be surgically removed, it's best to make sure you have a surgeon who will remove just the cyst (cystectomy) and leave the ovary or enough of it for normal hormone production. This is important regardless of a woman's age since the ovaries produce health promoting hormones our entire lives. This site is helpful - http://ovaryresearch.com/ovarian_cysts.htm.
Please keep us posted on what you find out.