HELP!

I'm currently 10dpo, suppose to get AF in 3 days, but have been spotting since 6dpo (5days now). The spotting changes colors from brown, to red, than back to brown but never enough to wear a tampon/pad. I see something almost every time I wipe. My boobs have been soar for 5 days now (which they get soar before AF but don't remember them being soar for 5 days straight). I had mild cramping in previous days, but usually I have terrible cramps when AF comes.... What could this be?!?! I thought implantation at first but this has been going on for days.....? Has anyone expericed this? I have no idea what is going on.... if I don't get AF by Thursday I will test, this has never happened to me...