is very much effective if taken within 72 hours or 5 days ( in some pills) after an accident. The sooner it is taken, the more effective it is. As such, she has very little chance of getting pregnant and this fact also depends on whether she is in her ovulatory phase or otherwise. You may wait till she is due for her next period and if she does not get it within 2 weeks after she is due, you should contact her specialist to exclude pregnancy
. Please remember, emergency pill contains high doses of hormone and as such, may cause a breakthrough bleeding
or may alter the normal period. Try to use some better form of contraception in future as emergency pill use should be restricted to a couple of times only during a year. Take care.