Given that there is so much overlap between the error ranges of the glucose readings, I wouldn’t worry too much about them. What were your ketone readings at those same times?
As for the upcoming doctor’s test, presumably he will be ordering more tests than fasting glucose. You have to take the numbers into account as a whole, not focus on just one. For example, your HbA1C and CRP numbers, your liver tests, kidney function tests, are all relevant. Unfortunately, the doctor will refuse to test fasting insulin, because there’s no drug to treat insulin levels.
Dr. Paul Mason, an Australian physician who has gotten into treating patients with metabolic problems, feels strongly that the absolute value of serum glucose is not nearly as important as the range in which it is operating. A higher, but narrower range is much better than wildly fluctuating lower readings, in his view.
One last thought: are you eating enough fat? If not, it is possible your liver is making glucose to meet your body’s energy demands. Once we are keto-adapted, our skeletal muscles actually prefer fatty acids over ketones and glucose, but if there isn’t enough fat to make ketones out of, gluconeogenesis kicks in. Remember that even if we are fat, there is a limit to how much fat our body will allow to be taken from storage in a day.