Hi, I am on the 3 month petogen injection . When I started using the injection in February 2010 I had irregular spotting (dark brown blood ). I then went to see a doctor and he just gave me another petogen injection and the spotting stoped (my period also dissapeared). I gained about 15kg s while being on the injection and in the past 4 months I have lost about 12kg s again. My spotting has been back for about two weeks now and I was wondering if the weight loss could be the reason for the spotting? And if it is not, what causes the spotting?