ovarian cancer after cyst rupture?

I am 34 and have the BRCA1 & 2 mutations, and have never had cyst problems until I got pregnant last August and they told me I had a cyst on my right ovary at my 8 week ultrasound. I remember them saying it was around 2 cm. It was still there at the 20 week ultrasound. I questioned the U/S tech about it due to my genetic issue, and she said it didn't appear suspicious. I didn't push any further. Doctor didn't seem concerned. I delivered my baby May 2 and exactly 4 weeks later started having very sharp pains where my left and right ovaries are & 3 days bleeding. The pain seemed to go back and forth between the sides and I . At my 6 week postpartum check, doctor said my ovaries felt fine by manual exam. The exam was very painful, which it has never been in the past. I asked for U/S, which was done last week. Tech said left ovary looked good and right one appeared to have had a cyst that had recently ruptured. Doc still not concerned. Went to ER two days ago with steadily more intense pain, mostly in area of left ovary, but sometimes on right. CAT scan showed 2.5 cm cyst on right ovary, and nothing on left. I am wondering how I could already have a cyst develop in one week since they told me I had one rupture. Also, why is the pain much worse on the left? And lastly, if the cyst that ruptured had been there all through the pregnancy and then ruptured, is there a good chance it was cancer and is now spreading through my abdomen? Would a benign cyst hang around that long (9+ months)? And why am I even getting cysts when I'm not ovulating--due to preg. & now breastfeeding? thanks