Hey,
I interviewed at Bryn Mawr this past October; and I just found out that I was accepted a few days ago! Actually, I found out via a phone call in CVS from the director, Jodi, and this resulted in an uncontrollable jumping fit of enthusiastic screaming and more than a few stares from confused patrons)
But anyway...Congrats on getting an interview!! They're definitely interested!
The interview itself is pretty chill. You just need to show them that you're supremely dedicated to entering medicine and have some knowledge about it; and that you understand the impact of your decision and the huge commitment it's going to take. If you are really serious about this and excited about becoming a doctor and can back it up with good reasons why, it's going to show and thats what they are looking for. On paper, you're good enough to be accepted; but now you just need to show them, in person, how ready and passionate you are about becoming a doctor. Just be genuine, honest and open and you'll do fine!
Good luck!
-dan