It is completely natural to feel anxious right now, but please take a deep breath. Yes, there is still a small chance of pregnancy, but taking the i-pill (levonorgestrel) at 68 hours is still within the recommended 72-hour window. While its effectiveness decreases the longer you wait, it still provides significant protection. To be sure, I recommend taking a home pregnancy test if your next period is delayed by more than a week, or about three weeks after having sex.