Last month my period was not normal. I normally have 5 to 7 days of really heavy bleeding and clots but I had 3 days of heavy bleeding and clots. I did a pregnancy test and got bfn. My next period is due tomorrow but I had sex with my so this morning and there was brown blood when I went to the bathroom. I am suffering with light headed Ness, the shakes, dieahera, really sore boobs and my veins on my boobs are like sticking out. Is there any chance of the brown blood being implantation or having sex has brought me on my period early. Any advice would be a great help.. just don't want to get my hopes up as I had a miscarriage 2 weeks before Christmas. .