. Is it normal that my glucose dropped so quickly from 6.8 to 5.5 mmol/L?
There is just 0.7mmol difference between these two results which is well within the accuracy tolerance of the meters.
The accuracy standard for all meters is plus/minus 15%. You could do two tests on one drop of blood using the same meter and get similar results.
The metres are not accurate enough to worry over a few decimal places, they just give a rough idea of what range our blood sugar levels are in, the 15% means if the result is 5mmol, your actual blood sugar level is somewhere between 4.25 and 5.75 a 1.5mmol range.
A result of 10mmol would be between 8.5 and 11.5 a range of 3mmol.
It's not perfect but it's all we have.
do I need to be worried? Is the reading a sign that I'm developing diabetes?
Your original Hba1c is at the top end of normal, it shows that perhaps you are not processing the carbs as efficiently as you have in the past. It sort of hints that maybe you are becoming resistant to the action of your insulin. Will you tip over border into pre diabetes and onto T2, who knows , not even your Dr could answer that with any certainty. Personally I would take it as a warning, and do something about it. nothing changes unless you change something.
when should I measure my glucose after finishing eating? After two hours? Is this the time when glucose reaches a peak?
If you test before you eat and again in 2hrs, the difference between the two results show what your meal has done to your blood sugar levels.
A perfect meal would see your 2hr result back close to the pre meal one. This would mean that any glucose coming from the digestion of the carbs in your meal, has been taken up by your insulin and used for energy.
Because as already explained the meters are not as accurate as we would like, we allow a 2mmol rise.
So in a nutshell, a 2hr reading no more than 2mmol above pre meal is acceptable.
Anything over 2mmol indicates that there were too many carbs in that meal, and that your insulin is still struggling to deal with the glucose that came from them.
I'm guessing that if you had tested just before your late meal of spaghetti, fruit and chocolate, done a second test say 90min later, you would have seen why most unmedicated T2's wouldn't go anywhere near a meal like that