I'm doing shared care, and I have an OB appt at 34 weeks. I think its just routine - they'll just want to ensure you're travelling ok.
I am personally going to use this appointment to discuss my birth options - take in my birth plan and talk about my wanting a physiological 3rd stage.
That's a thought, probably at this appointment they will ask for your consent to the synto shot, and to the vit K and Hep B vacc for bubby. You might want to have a think about whether you want to consent to those before you go along. You could also use this appt to discuss any hospital 'policy' you're unsure about (like whether they have time-limits for each stage of labour, etc.)