Spotting and still on the pink pill?

I'm 4 pink pills away from my blue pills which will start my period. I am really good on taking them on time and I've never missed a pill. the lastest I ever took a pill was 17 mins after my time which happened Sunday. Today I just used the bathroom and I saw blood on the toilet paper. It wasn't too much, but I'm a little worried. Is it possible that I'll be getting my period early even before i have taken the blue pill?