My mom had Uterine Cysts and I remember her saying her back would hurt alot. She had one the size of an orange.I have Ovarian Cysts and was diagnosed with P.C.O.S. and only have 4 ''regular'' periods a year. With cysts in this location you will get alot of pain on the sides where your ovaries are. You didn't specify where they found the cyst. But from the sound of it, it seems like you have it in your Uterus. You should try to get an appointment with another OBGYN that can see you sooner. Cysts can get really painful and heavy and I wouldn't want you to be in too much pain. Good luck.