I've been on birth control for a year now. This past month, I did not get a refill becuase I haven't had time to get back to the doctor's office. Well, my period is now 5 days late. Is there a reason for this (besides pregnancy)? I'm not sure that I am pregnant, becuase I haven't had any of the symptoms that I had before. I had horrible headaches the week that I missed my period and tender breasts, but I have not had those symptoms this week.