Hello, Thanks for sharing your health concern with us. Firstly, if you had the intercourse during your safe or non-ovulation period of the cycle, you cannot conceive. Ovulation occurs two weeks ahead of the next period and this is when an unprotected intercourse can lead to pregnancy. Secondly, as you took the emergency contraceptive pill within the stipulated time after the intercourse, you are protected well. The high hormone content of the pill can cause menstrual disturbances and delay the next natural period by a week or two. Hope this helps.