A few years back, I had this series of A1c's:
The October, 2010 result is not credible to me. There was no appreciable change in my treatment plan or lifestyle to justify a drop from 6.8% to 6.0% and a return to 6.6%.
As others have already stated, there can be many reasons for your recent result that have nothing to do with your overall BG control. You are mindful of your eating, exercise, and insulin program as well as doing abundant fingersticks. I would consider the 6.9% result an unrepresentative outlier unless and until subsequent A1c's confirm this number.
I went to the lab for an A1c last week. My BG was high at the time, two fingersticks were 167 and 194. My overall control over the last three months was very good. My meter and CGM both listed my 7-day average at 114 and 30-day average at 113. The 30-day CGM time in range, 70-140, was 77%. I'm curious to see if the high BG at the time of the blood draw has in inordinate influence over the result.
In the end, the A1c is a number subject to many flaws. Maybe we should append all A1c's with an "-ish" suffix!