"i had unprotected sex three days before ovulation, and took this within four hours after having sex. after reading some of the reviews, i was a little wary of how well it would work. i ended up experiencing my normal ovulation symptoms as well, which made me even more worried as this pill is supposed to prevent ovulation. i didn&#039;t experience any side effects (no headaches, nausea, etc), but i did have some cramping that began about four days after i took it, and continued off and on for about a week. my period ended up coming today, which is three days before i expected it. give it time and try not to worry!"