Implantation bleeding or hormones?

My husband and I just got married 9/4 and are TTC our first baby. I stopped taking BC at the end of September, had a normal period and did not start taking it again. Today I experienced some light bleeding which concerned me. Before BC I never ever had mid cycle bleeding. I'm wanting your opinions; am I starting my period already? Is it implantation bleeding? (I missed a pill around 9/20 otherwise I know it's too early for this cycle) or am I getting spotting during ovulation for the first time? I'm confused and worried, this is totally abnormal for me...