Hi, I was diagnosed with Endometriosis three years ago via Laparoscopic Surgery. My Gynaecologist believes it has returned and I had a three month injection of Zoladex three weeks ago. From my discussion with my Gynae, I thought I wasn t supposed to have any periods for the duration of the injection (three months). I however got my period four days ago and the pain is terrible. My question is, is there any reason of why I got my period, did the injection not work for me?