light spotting before period

I'm due to get af on Saturday (in 3days) but have had a little bit of very light brown blood and a few specs of pinkish blood today when wiping. Sorry for tmi! 
Been trying for a few months and finding it so tough. This is the first month I've had any kind of spotting so wondered if anyone else has experienced it? I've read it would be too late for implantation 
Also had mild stomach cramping the last couple of days, again not normal for me this early.