I have been taking Yaz for approximately 5 months and my period has been pretty normal ever since. When I was not on birth control my period was sometimes all over the place. The past month (October) I got prescribed Fioricet for my tension headaches and was told by my pharmacist that it would interfere with my birth control. About a week after taking this medication I had sex and a condom was used. A few days after this I got strep throat and was perscribed ammoxicillan, which I was again told would interfere with my birthcontrol. Tomorrow my period will be two weeks late. I took a pregnancy test when my period was 4 days late and then again when it was a week late. Both test came back negative. I noticed a clear, almost sticky discharge last week one day and it made me somewhat nervous. As much as I don't think I am pregnant, I cannot stop thinking about the possibility that I am. I am currently 4 hours away from my regular gyn and its been difficult to get a hold of anyone to answer my questions. I have not started taking my birth control for this month and I don't want to until I know that I am FOR SURE not pregnant. I plan on taking another test tomorrow. I guess basically my question is does anyone think that my medications have interfered with my cycle??? Thanks