I know this isn't an exact answer for this year but I know a lot of my classmates interviewed after December 1st. For some reason UCLA tends to interview a lot of its eligible applicants well after December 1st. From what I understand though UCLA doesn't interview very many people they won't end up offering so I think they take more time looking at applications than some other schools.
Don't worry too much about it now. You have don't everything you can and now you just have to wait. (I realize that is easier said than done, I was in your shoes once, but take it from me worrying about it and trying to analyse your chances of acceptance doesn't help much)