emergency contraception
"I took this pill 19 hours after our condom leaked.  My period had just ended, so we wanted to be cautious.  I took it on Jan 4, 5 days later I had some abdominal cramping, a severe headache and cramping.  The bleeding and cramping lasted 4 1/2 days.  I also had some very minor light headedness off on of during January, but I'm not sure if it was really caused by the pill or not.  My next period was very late, I usually have a short cycle, about 25 days since I don't use birth control pills regularly it's length is irregular, but mine came a full 7 days after my longest cycle of 28 days.  It started on Feb 2.  I did have more cramping the week before it started.  The cramping was not fun, but at least it worked."