Hi frailfairy. In my experience the cysts feel differently depending on the type and size. When I had the chocolate cyst from endometriosis it was large like a grapefruit and felt like pressure. When I had the smaller cysts that ruptured I had intense stabbing pain...these were not from endometriosis. I had several ultrasounds but it was the CT scan that showed the small ones. Endometriosis requires a laperoscapy for proper diagnosis. Feel free to contact me if you have other questions.