why do I always spot before AF??!!

Beth
I always seem to get spotting from 8/9dpo. I've looked into low progesterone but don't have any of the other signs of low progesterone so I'm not sure and my temps aren't low near the cover line. It always seems to start just after I get a temp dip which I initially thought was an implantation dip followed by IB but 9 months down the line I now know it isn't!!!! Can you see anything from my chart at all???