hi, welcome to the forum, im no expert but i believe hba1c numbers are higher than that, thats either mmol or % in other words which either scale we are using it isnt hba1c but is a very good number and wouldnt be worrying about it at all
Some doctors still prefer to work in%. They would like us to be below 6.6% (48mmol) and ideally below 6%(42mmol). So your results of 5 (31 mmol) assuming it is in % is excellent.