2 days ago me and my girlfriend had sex. I used the withdraw method and didn't come inside her. Right now I am extremely paranoid that should could possibly be pregnant from pre-cum or possibly me ejaculating a little before pulling out.

She says she is on Birth Control but she can't (for some odd reason) give me the name of it because she doesn't know what it's called. She took the morning after pill the following morning (it was withing 12 hours of us having sex). Also, we had sex the same day she had gotten off her period.

What are the chances she could be pregnant?