I dont know if this is because I have endometriosis (not severe) or if its just cos I'm getting on a bit. I have up to four days of brown mucous (sorry if you are eating) before period properly starts. I have had conflicting advice about whether to count day 1 as first day of proper red bleeding. Seems to me that first sign of the brown dsicharge is the endometrium(?) starting to break up so the hormones must be kicking in then. Does anyone know?