Light brown spotting 3 days before expected AF..

I have had light brown spotting for 2 days now! It's so light that I don't have to wear a panty liner. Just when I go to the bathroom I notice it! It seems to be fading away. AF should be anyday now. Hoping its Implantation bleeding... Possible? Has anyone gotten a BFP from this?? I'm praying I get one! I'm on cycle day 40.