What to expect 1st apt if I'm already 24 weeks

I'm 24 weeks now, just found out I was pregnant about a month ago. They couldn't get me in until the 24th. Does anyone have any idea what to expect at my 1st apt since I'm so far along? I figure mine may not be the same as someone going in at 5-8 weeks. I've seen a primary twice, once in June & once in July and also recently went to the ER worried about the baby. All 3 times they took bloodwork & ER did ultrasound but I didn't even see it that well and wasn't told the sex. Should I still expect bloodwork if I have recent bloodwork done? Also ER said they may not do another ultrasound, how true could that be because I want another to know the sex & that I can keep.