Hi Anonymous and thanks for your question.
No contraceptive guarantees 100% prevention of pregnancy. The following information is provided by the manufacturer of the emergency contraceptive you used.
The sooner you take it, the more likely it is to work. Ideally, you should try to take the tablet within 24 hours following unprotected intercourse, as this is when it is most effective. The efficacy depends on how many hours have passed since you had unprotected sex: • Within 24 hrs - 95% • Between 25-48 hrs - 85% • Between 49-72 hrs - 58%
Hope that helps,