I am 46 yrs old, take NECON birth control pills to control a very heavy period. I was told a year ago that I have an enlarged uterus and should have a hysterectomy. Today I am on the second day of my period, it had not gotten heavy yet, and I passed a large piece of gray/white tissue. It looked to be about the size of an egg, seemed to be similar in shape to an egg, with a hole in the end about 1/2. What could this tissue be that I passed. I am not currently sexually active, so am not concerned that it is anything to do with a miscarriage.