"i am 255lbs/5&#039;1 height and 33 years old. i say this because i read many reviews and doctor&#039;s explanation that the pill sometimes does not work on obese or overweight people. it worked for me. i took it within 4 hours of being intimate with my boyfriend. you feel like you are pregnant because for at least 5 days i felt like activity was going on in my uterus, and the day before my period arrived i had really bad cramps, when i have not had cramps since i was in high school, at 120lbs and a size 2. yes, it throws off your period. i was not due to have my period for another 2.5 weeks. however, my period came 7 days after being intimate and taking the pill, immediately. so, it works! you might be a little paranoid and feel like your pregnant because of cramps and what feels like activity going on in your uterus, but it works!"