So My Girlfriend And I Had Decided To Have Sex

So my girlfriend and I had decided to have sex without a condom, I did finish in her but we were going to get a plan B pill the next day. Instead she took two birth control pills because that is a method that her friend had used before. I didn't feel that was good enough so roughly 48 hours after we went to get a plan B pill. Is there a chance that she is still pregnant?