Early Bleeding on Ortho Tricyclen?

I have been on Ortho Tricyclen for a year and a half with no problems and no breakthrough bleeding. I have two active pills left before I start the inactive pills and usually I don't start my period until late day 3 or early day 4 of the placebo pills. However, today I have medium bleeding (started out light pink and is now fairly heavy red). I am taking Lamisil orally for a skin problem... could this have affected my birth control? Should I be worried about this?