This happened in Nov, 2016. We were having anal sex and my husband pulled out before he ejaculated but he ejaculated on my thighs and near my vagina. I washed off immediately. Although I was sure it did not even touch my vagina but to be safe I took I-Pill within 24 hours. I had my next period on 2nd Dec, 2016. My Nov date was 4th Nov. After that my subsequent period was also on time on 31st Dec, 2016. Both these periods were normal flow-wise and duration wise. My next period was due on 31st Jan, 2016 going by the date. I always have my periods in +3/-3 range of earlier date. But today is 3rd Feb and I have still not started with this month. Also, since November itself we have been doing anal sex but we always did it in standing position and his penis never touched my vagina. I always covered my vagina with my hand. Also he never ejaculated in me or near me since then. He pulls it off before and rubs for a minute with his hand to ejaculate. What could be the reason that I am late? Is it because of I-Pill? I took it for the first time.