Brown Period Blood

This is kinda an old thread, but whatever. There will never be old blood from the previous month. Your body is pretty skilled at cleaning itself out. Once is sheds the top layer of your endometrium (the lining of your uterus) it begins to rebuild it again for the following month. Mine is sometimes a lightish brown when it's a lighter flow, like at the beginning and end of my period, but it's always dark red of heavy days. It's normal.