Implantation bleeding?

On Tuesday I was getting ready for work and had light brown cm. Went to the bathroom to wipe and was confused because AF isn't expected until Saturday and I havent had any more spotting since could this be implantion bleeding or a fluke? (Sorry for the TMI). I checked cm for two days and there was no more brown cm just creamy white until today now 1 day late for my period I have brown cm but no spotting. AF was due yesterday.