i have a cist on my ovary

i miscarried back in november and had a ultrasound just before i miscarried because my ob couldn't hear the heart beat. they checked my ovary's kiddney and so on. scense i miscarried i have had really bad cramping that should be gone by now. so we did another ultrasound and found out that i have a cist on my ovary that appeared after the miscarrage. it the size of a peacon in the shell. i'm scared because they wont remove it for a few month's the want to see what it dose beacuse some times the desolve. my aunt had a cist on her ovary and it went for 1 to 6 in a matter of 3 month's she died from it becoming cancer she died 5 month's after finding out she had a cist.