Honestly, this is really something best discussed with your gynae, ovary cysts during pregnancy can vary quite a bit depending on the size and type, so the scanning schedule really depends on your individual situation. A few of us in my mum group had cysts, and some were monitored every few weeks while others were just checked during routine scans, so it really differs lah. Your gynae will know what's safest for you and baby, so don't hesitate to ask them directly about the monitoring plan, they'll explain it clearly!