So confused.. Help?!

Okay so here's what I'm confused about, I got my AF earlier this month (Sept 18-23) I also have been having painful/sensitive breasts since Sept 6 and it's still here and it's currently the 30th. But the thing is I noticed I spotted yesterday a very very light brown spot and today I noticed quiet alot more dark brown spotting, more like the first day of your AF. I went to the doctors yesterday and they sent me for some Blood work to see if I'm pregnant or not even though the 4 pregnancy tests I did all came out negative. I just dont understand why I would have my AF and spotting, im ttc #1 and glow says my fertile days don't start till the 3rd of October. Could it be IB or is my body just messed up, I don't get it?!