Breakthrew bleeding and spotting

Well I got my period last month (march) on the 28th. My cycle is very short usually but pretty consistent. Since I officially stopped my period I have had a pinkish red bloody kind of discharge or thickened blood as if it was old left over blood no scent and no pain or itching. No abnormalities other then the discharge its self. And I was supposed to get my period yesterday ( usually get it a day sooner then projected) i Took a pregnancy test at the beginning of last week with a negative result. Any ideas what this could be from or what could be causing it. We have been trying since about July to conceive, could this be it?