Hi angelyn
Personally I agree with you, having those sharp cut off points of diabetic/not diabetic can seem very random. It's to do with the normal curve (if you'd ever done any statistics?) and so it is the decision to make a cut off point at a place that makes sense statistically. Even the World Health Organisation has changed its mind about where the cut off point is, compared to what they used to think.
Anyway, the doc uses it as a guideline. When it's to do with your personal diagnosis though it can seem a bit strange.
"Normal" blood sugar (the range most people have) is roughly between 4ish and 6ish. When I was diagnosed with diabetes my blood sugar was over 25.
So as you see, you are right on the edges of normal/getting a bit high - your body may be finding it harder to store blood sugar. The higher the sugar creeps up, the more you risk getting other problems (diabetic complications) - which it's why it's a case of, don't panic, but wait and see what happens next, and maybe make some lifestyle changes that will help your body out.
does that help?