Hope you feel better soon! I had a cyst removed from my right ovary seveal years ago and I don't know exactly how big it was but I know it was not 12 cm. It was probably more like 3 or 3.5 c.m. I had lower back pain when I layed down. Anyway, I was sore for awhile but not in pain at 4 weeks. At least I cannot recall that. I'm curious as to what your doctor is saying.