emergency contraception
"Had unprotected sex the day after my period ended. Took the pill within 35 hours after sex. Experienced headaches and tender breasts for the next week or more. Then nothing really. The week of my next period there was a very light flow of a dark red, clumpy discharge. I thought it was spotting and it lasted about 2.5 days. Then nothing for a day. Then I had the worst headache ever and stayed in bed for hours. Later realized this was my period and it had been right on time. No pregnancy."