My boyfriend and I had protected sex last September and my period came that same month. We didn't have sex on October because we were not in the mood. I'm confused because my period is late and I know that that's not the reason since we didn't do it.  I was suppose to have my period on October 25 and today is November 4. Also, I just started drinking alcohol last october. Does that cause delay? I know stress can make my period late but I just can't stop thinking about it. Please help me!!!