Taking my first OAT end of Dec, is this too late?

I know I can't get an interview without the OAT scores, but I would like to reschedule the exam to the end of this month instead of 12/9...not much difference, but I am super nervous!!

I know it takes 3-4 weeks for the schools to receive the official OAT scores, so they will have my scores in late January.
I am worried that most schools already will have full classes by then..

so...Should I just keep the date as it is?(12/9/14)
Thanks!