Slow progress: how to get below 6.0% A1C?

I was diagnosed with T2 last June with an A1C of 7.4% (27, F). I went on a low carb diet and started exercising regularly. I wasn't prescribed any medication.

Since last year, I've lost 20 pounds. This April, my A1C was 6.3%. I went back to the endocrinologist yesterday and my A1C was 6.2%. (boo)

Does anyone have any experience with getting their A1C below 6.0% without having taken any medication?