Taking the i-pill (levonorgestrel) twice in five days delivers a high dose of hormones, which frequently disrupts her natural cycle and causes prolonged bleeding. While this hormonal imbalance is the most likely cause of her 10-day bleeding, there is still a small chance of pregnancy, as emergency contraception is not 100% effective. I reassure you that this bleeding is a common reaction to repeated doses. However, to be safe, she should take a home pregnancy test three weeks after the intercourse. If her bleeding becomes very heavy or is accompanied by severe abdominal pain, please consult a doctor for a quick evaluation.