I have had AIH for 1.5yrs. Mine was actually diagnosed quickly because my ALT was 848, AST was 748 and bilirubin, initially, was 9 but climbed to 23.3 in 2 weeks. So since it was a severe onset...it was a pretty quick diagnosis with blood tests about every 2 days to test for everything under the sun (since I was turning that color ). I was in to see a specialist 1 week after the jaundice and initial blood work was done and had a biopsy at the 2 week mark. I had started prednisone the night before the biopsy and responded very quickly.
So, I would say, from everything I have read on the illness, not to worry if they are waiting to retest. It appears that some people remain mild and don't have treatment right away. If your symptoms change whilst you wait....go back to your GP and either press the issue of seeing a hepatologist or request another blood test earlier.
Please keep us posted on how you are. You'll find this a great site with many supportive people.
Diagnosed with AIH January 2007
meds: Azathioprine 50mg + Prednisone 5mg