Hi, Congratulations!
I'm 20 weeks and have my antenatal appointments at the Southern. You'll get a scan - very exciting, and will also have an appointment with a midwife. I found that on the day of my 12 week appt, it was very busy, with lots of people waiting for scans. I think it's a clinic which runs on a 1st come, 1st served basis, so there can be a bit of a wait. You should get a couple of pics of your baby too.
The appointment with the midwife runs through all the "do's and don'ts" (a bit late if you ask me, they give you all the info we probably should be given as soon as we find out we're pregnant). They will take some blood samples, and ask you about the tests you want to have.
You'll also be asked to provide a urine sample - following your scan, as you should try to have a full bladder for this (so you get a clearer image I think?), and will get your height and weight recorded.
I took along a list of questions to ask, as I felt that by 12 weeks I had so many questions I would never remember them all! The midwife was really helpful, and took the time to answer all my questions. I was also booked into parentcraft classes, which apparently fill up far in advance.
You should get an appointment while you're there for your next scan which will be at 20 weeks.
Hope this helps, enjoy! :)