I was given a Z pack for a respiratory infection, and I started taking it on 11/1 and I took the last pill on 11/6. While I was taking the Z pack, I started the inactive pills of my birth control, and had my period on 11/6 (the last Zpack pill also). I started my new pack of active pills on the 11/9 (tues). I have been taking them everyday at the same time. I also have used protection throughout this month except for today 11/26. We started off with unprotected sex and then we used a condom, and he ejaculated in the condom. My period is scheduled to come on in one week (12/3). Did the antiobiotic affect my birth control the whole month? Is there a chance I could get pregnant??