ovarian cysts, pregnancy, and ultrasounds

I currently have an almost 3cm cyst on my left ovary. Occasional pain here and there. I am 10weeks pregnant. Times I had an ultrasound was 6 weeks and 7 weeks. Do you think they will give me another ultrasound before getting the "gender" ultrasound at 20weeks? I didn't know if they would monitor those things or not. Doctor said the cyst should go away once the placenta has completely taken over at 12 weeks but the key word is should. Just by past ultrasounds it has not shrank at all.