Cysts while pregnant?

I’m wondering if I’m alone in this? I have a pretty complicated medical history but yesterday found out I have a large cyst to the left and behind my uterus. I’m trying not to stress, I know its not good for the baby but if there’s anyone with some insight I’d be forever grateful. My normal OB is sending me to a university because of my history to have it checked out. She tells me she’s not too concerned but would rather have it checked out to be safe.