Could I be pregnant?

So I had sex with my bf on 3/18 which was the last day of my period. I just started a new brand and dosage of birth control pills on 3/17. I have been on birth control for over 2 years. We used a condom but it broke. He pulled out before he finished though. I have really sore and tender breasts and i’m feeling more tired than usual. Could I be pregnant?