HELP!

My AF was due 8/4/15. I tested 8/1/15 & 8/3/15 both were negative. On 8/4/15 I was spotting, then by the end of the day I was medium. On 8/5/15 I was medium, on 8/6/15 I was light that morning and by the end of the day it was pretty much just brown streaks. once I showered that night I put on a fresh liner when I woke up on 8/7/15 it was literally just a brown dot on it. My cycle usually last 6 days. Can someone shed some light on this situation for me please..