Question - Advise

Bec
AF is due tomorrow 
I had some very light cramping 3 days ago but not my normal AF is coming cramps ( at all ) which is odd for me. 
Last night and today I've had some cream colored light pink and deep brown spotting ( not getting heavier ) with no cramping. 
I don't feel any symptoms of anything! AF or pregnancy when usually my body gives me all sorts of both.
Last night I had trouble sleeping but that's it. I tested last night and it was negative of course as always. 
Could this be late implantation? I know I just need to wait and see but as you all know that's really hard :( 
My bbt was at 36.6'c yesterday morning and down to 36.35'c this morning. Yesterday was my first time temping so I have no idea what my average is.
Any input would be great