Is Pregnancy Possible Despite Taking I Pill Post Unprotected Intercourse?

My girlfriend and I had done sex 5 times in 1 day and she had taken i-pill within 3 hours from the last time. She had taken another i-pill on the same day in evening. We have done it in10th march and till now she has not got her period?? Is there any chance of getting pregnant. Plz help us.