Hallow Dear, You have started the next pack of contraceptive pills in time. 12 hours delay once in a while during the cycle is permissible. Moreover, this delay was just at the start of the menstrual cycle. At this time, for practical purposes, no egg is released by the ovaries for fertilization. The egg is released 14 days prior to the next cycle when you are not on any contraceptive pill. While on contraceptive pill, there is no egg release. The released egg has life of 24 hours and the sperms are active for 72 hours. Hence period of about a week around ovulation is considered as fertile period. However, since you are on contraceptive pills, even that possibility does not exist. Dear Madam, you are well protected against the pregnancy. You need not take emergency contraceptive pills after this incidence of unprotected sex; because basically it is not an unprotected sex - you are well protected. I hope this releases your stress. Dr. Nishikant Shrotri