i interviewed at ICO, and i felt like i wanted to cry afterwards because everyone else looked as if their interviews went so smoothly. my interviewer was different. he focused on my C's in physics =/ and how i had gotten an A in math, and he expressed concern and didn't understand how the 2 weren't related in performance. at the time of the interview, i hadn't taken the OAT yet, so believe me when i say i was nervous and felt even more pressure on doing well on the OAT, especially the physics section. but i ended up with a happy ending because i did a decent job, and i was accepted. =) don't stress too much, i'm sure it'll be okay. i felt like my interview was a disaster, but they ended up accepting me.
good luck, i'm crossing my fingers for you!