Early period on Birth Control

So here the story: I went out Saturday with Friends and totally forgot to take my birth control pills. This is the first time I have EVER forgot to take a pill and I been on for three months. Well today I got my period, I'm bleeding and cramping; but the thing is I have 4 blue pills left before I get to my brown ones. Am I just spotting? Like should I call my doctor? Or is this normal?