I had sexual intercourse on the period due date.can i get pregnant? i took postinor 2 later but just before 72 hours

Pregnancy: Chances are very small that you can get pregnant, that close to your period, and using the plan B. The only way you will know for sure is with a pregnancy test, especially if you miss your period. This might be a good time to consider regular birth control. Why sweat it out every month? Also, remember that plan B doesn't protect you from STDs.