<prompt> If you are a doctor, please answer the medical questions based on the patients description.I am using the birth control yaz. This is my second month on it and the first month my period came when i was on my 3rd white pill and it ended up lasting a week. I had unprotected sex while i was on my last active pill and now i am getting ready to start my new pack on sunday and i have not gotten my period. i know there is a possibility of pregnancy but how soon is too soon to take a test and get accurate results?  <response>: Hallow Dear, Birth control pills have almost 99 success rate in preventing the pregnancy. You had period while you were on the 3rd white pill. It is fine. You should get period in this month also. I do not feel there is any reason to worry about. Please do not wait for the period to appear; start your next pack on Sunday as scheduled. The pregnancy test on urine gives reliable results about 8-10 days after missed period. These test are best performed on the overnight morning first urine sample. I hope this helps you. 