Hi, Ive been taking cerazette birth control for the past 2 and a half weeks. I missed 2 pills, Friday and Saturday, then took one again Sunday and again Monday. I had unprotected sex Monday and Tuesday morning, and can't take my Tuesday pill because I'm out of the house and can't get to it, what are the chances that I could fall pregnant? If you miss a couple of pills are they completely ineffective for 7 days or does it just lower the effectiveness?