Sooo... you wore a condom, didn't ejaculate, she's on the pill AND has had a period since then, and you're still worried? What, do you think you produce some kind of miraculous super sperm that can teleport straight from your testicles into a woman's fallopian tubes?
Buddy. Chill. You're both being responsible about using contraceptives (which I commend you for, it's the right decision), so have some trust in your GF, all right? Even if she was taking her BC incorrectly or for whatever reason it wasn't fully effective, as long as YOU are using condoms correctly and consistently they are very effective at preventing pregnancy. Accidents mostly happen with incorrect/inconsistent use.
Oh, and PLEASE don't get your friends or family involved in your relationships issues anymore. Have enough respect for your GF to keep private matters private, m'kay?