My deepest condolences. Misscarriage really does a job on your mind. My first pregnancy resulted in misscarraige at 8 weeks.
Since you are BRACA2+, and you have taken substantial fertitlity meds, even if your current blood pooling issue resolves itself, I would still be very cautious for cysts in the future.
Fertility meds stimulate the ovaries to crank out alot of eggs and hormones and do put many women into 'cysty' situations.
If you continue to find yourself uncomfortable, trust you own judgement and tell doc you've had enough and need to solve this problem.
First let me offer my sympathy. I lost identical twins yrs ago at 8 mo. pregnancy. They only lived overnight due to size and uneven blood supply from being only one placenta.
I looked up the cyst and it said usually surgery was not needed to remove the blood. If it persists 7 to 10 days , however, they may have to remove it. Did they ever actually see the cyst? If you are concerned you might insist they remove it and biopsy it, or get another opinion from a doctor. Best wishes