"plan b was taken sept 15th, 1 hour after our incident when condom broke. i took the one pill and a few hours after started feeling terrible cramps. the cramps only lasted the day i took plan b and never got them again. 2 weeks later, i got my period. this period was very light, and lasted only 4 days when normally my periods are heavy and last a whole week. i was happy i got my period but was still worried. the next month, oct, i waited for my period. i didn&#039;t come. i missed my second period and at this point was taking pregnancy tests every week. they all were negative. on nov 11 i got my period. so, it works! very pleased with plan b. but you may have a delayed period. so don&#039;t freak out. its a side effect."