Period late

I have been off my birth control since my last period ( November 6th ) I had my period then and was due for my next December 4 and still nothing I've taken 2 test and both were negative. Could I be just running  late or is it possible I'm pregnant? I've never been late since I had my son and got on orthro evra. Even the times that I missed putting the patch on and when I went two weeks without it.