Hello, I have gone through the query and understood your concern. Your friend had the intercourse during the fertile or ovulation period and as a result, her chances of conception are high. Yet, since she has taken the emergency pill soon after, she is 80-85 percent protected. She may expect some withdrawal bleeding after a couple of days after the pill use. Her next natural period also may get delayed by a week or two because the emergency pill contains high dose of progesterone. If she becomes overdue by ten days, she has to see a gynecologist for further management. She would then need to exclude pregnancy and go for a trans-vaginal/pelvic sonogram before a period is induced if pregnancy is negative. Please note that emergency pills should be used only for a couple of occasions a year and regular contraception is preferred to prevent accidents. Hope this helps.