emergency contraception
"My husband and I have 3 kids and are very good about tracking my ovulation cycle to prevent pregnancy. This particular time we had sex my calculation was one day off. Within 24 hours I caught the mistake and within 36 hours took the plan b pill. My period is like clockwork so when it didn't come, I gave it another week, and took a pregnancy test and I was pregnant. I think plan b just makes you think it worked but 9 times out of 10 most of the women who take it aren't aware of their ovulation cycle. I pay close attention to my body and when my period didn't come on the expected day I knew I had to be pregnant but waited it out to make sure. I would bet most women aren't even ovulating when they are taking plan b to ward off pregnacy."