I just saw this and thought that I would post.
We go to a family practice. I asked the NICU before we left and they were fine with it. Our Dr. is pretty good with her being premie but I do usually remind them. I remember at her 4 mo. apointment he asked if she was rolling over and I said "no, but she was 2 mo. premie" and he said "oh, well she'll probably start to do that in a month or 2". They also have never told me that she was too small or anything, but I know this varies with Dr.'s so you have to find one that's right for your family.