Implantation ???

Ok so I was about 8 days before my expected period I noticed when I would wipe that there was a lil spotting it was a light pink/peach color, only when I would wipe, not enough to even fill a panty liner, light cramps.. I usually never spot between my cycles so now I was expected to start my period on Monday and we are now Friday and I still have not got my period!!! What could this be ? Implantation or a cycle change? I'm confused cus I'm always on time when it says I'm gonna start