Could The Contraceptive Pills Be Effective If Started Before 11 Days Of Intercourse?

This past Sunday night, my boyfriend and I were initmate, and didn't realize until afterwards that the condom had broken and he had ejaculated inside me. I had started a birth control pill 11 days prior to the incident, and had taken them at the exact same time everyday. Is there still a high possibility that I could get pregnant, and if so, is it too late to use the Plan B contraceptive?