I found that the 'not knowing' was more stressful than the actual diagnosis. Most of my work-up (labs) was done by the time I made it to the rheumy.
He did a physical exam-checking ranges of motion, checking for stiffness, swelling, etc, of joints. Asked questions about family history, other illnesses. Usual stuff that any consultation doc would do. He ordered lumbar spine and SI joint xrays. He didn't come to a final decision on diagnosis right away, which miffed me at first, but my x-rays were essentially normal. It took 6 months for him to finally say 'inflammatory arthritis' although he's treating it like it's AS at this point.
If your case doesn't seem totally clear, you might not get a firm diagnosis on your first visit. At the same time, if your symptoms are textbook, he will still want to do some x-rays to see for sure. I can't imagine that you wouldn't have to have x-rays. If you have had some before, you might want to get copies to take with you. Same with lab reports.
But I'm in US, so all that might be totally different in South Africa. Anyway, good luck with the visit.
