I started birth control for the first time ever last month. I started the active pills on the first day of my period which was on the 11th of September. After being on the pill for 11 days and taking it perfectly (exact same time every night), I engaged in sexual activity but used a condom and withdrawal method. I'm now to the first placebo pill and haven't started my period. I'm worried to death I may be pregnant. Was 11 days and a 1st day period start enough time for the pills to become effective? I've heard from Planned Parenthood that if you start on the 1st day of your period then you're instantly protected against pregnancy. However, my regular on/gyn's nurse told me I should have given it a month. I feel like that answer was to protect herself and their office for liability purposes. Is the chance of me being pregnant very low?