Hello Sir, With My Wif I Had Sex On The

Hello Sir, with my wif I had sex on the date 17.09.2015. Primarily we were sure that nothing to worry because ejection was out side of vagaina. So we took no other action. But we are new couple. So, we wouldn't take any risk. Then after 30 hours she took a i-pill. It was first time she took any kind of pill. Her normal period date was 03.10.15 . But today is 15.10.15. What happening doctor? Please give me an answer.