Ovarian Cyst

Hi all! I need some opinions on this. A few months ago I went to the ER with pain in my lower right abdomen. I knew it was ovarian pain. They did a CT scan and I was told I had free fluid in my pelvic area, and the pain is probably from a cyst that maybe ruptured. They told me I should go see my OBGYN. So I promptly made an appointment. Two weeks later I went to my gyno and he said the CT scan showed cysts (or a cyst) I can’t remember and he performed a pelvic exam and Pap smear. He basically just told me I have ovarian cysts and to take birth control pills. I told him I’m not comfortable taking the pills because I can not find a pill that works for me, I’ve had horrible experiences with them. So basically he said just said give it time, it should go away. Now a couple months later, my periods are normal/regular but I still occasionally get a pinching pain where my right ovary is. I guess my question is, how does my gyno know my cyst is benign (non-cancerous)? I’m so worried it is something serious. I’m 21 and I’d say I lead a pretty healthy lifestyle. Has anyone else had this experience? I should mention I was on birth control and got off of it last February and it caused my hormones to go crazy, which I think caused the cyst(s). Can someone give me some peace of mind? I guess I’m worried it is something serious because I still occasionally feel that pain. 😞