Hi and welcome to Healthcaremagic. Thank you for your query. I understand your concerns and I will try to help you as much as I can. You probably have polcystic ovarian syndrome which is know nto cause hormonal imbalance that lead to weight gain. At this point there is no need to be worried but further steps are required to ruled out malignancy completely. It means that CT scan or diagnostic laparoscopy should be done to evaluate it more accurately. Generally, cysts should be managed surgically i cysts are larger than 5cm, bleeding cysts, torsioned or ruptured and it means that cysts became complicated and may cause specific pain. Also, if there is polycystic syndrome as underlying cause then hormonal therapy is indicated. Pain is usually placed deep in pelvis on affected side and may be associated with nausea and fever. I am sure that this will be just a benign cyst at the end but these further steps are required to ease your minds. I hope I have answered you query. If you have any further questions you can contact us in every time