I was for two years on progesterone pills, stopped my pills in December and went on to zoladex. My first month was heavy bleeding on the injection...and now second month too having like a breakthrough bleeding on and off nearly everyday. My gynecologist. Says it the breakthrough bleeding from the progesterone. But I am finding it hard to understand how long will this progesterone effect stay in the body. My gp says this particular injection is only 3.6 mg....it will take time in the body to settle. The big question is how long. Another gp says you can bleed on zoladex too. Some says it's my endometriomas that are bleeding. I don't know whom to understand..but I am fed up of this bleeding. Please help me.