hi im a dr
ur blood sugar level is perfectly fine
if u are a non diabetic, generally for random blood glucose our aim is < 7.8 mmol/L, if fasted < 5.6 mmol/L
As someone have mentioned above, hba1c is a better indicator of ur control of blood sugar as it reflects ur blood sugar level over the past 3 months as opposed the one that u took, which is just a one time reading.
however do note that certain medications can affects ur sugar level.

If u have not taken anything in the past 8h we will take it as fasting blood sugar, and the normal value is < 5.6 mmol/L, in ur case urs was 5.9mmol/L
According to our malaysian clinical practice guidelines, fasting blood sugar of 6.1 - 6.9 mmol/L are labeled as prediabetic, >7 is diabetic
so i wouldnt label u as prediabetic yet