Just did a re-test and it was 4.3If you are taking no blood glucose lowering medications then your liver should respond and release some glucose which will bring it up naturally. If you are as low as that and it is typical then you could be a little more lenient with the carbs you have for dinner.
Sometimes an unusual result is worth a re-test.
It is only my second day testing, but today is lower than yesterdays results.
This particular test though I have not long been back from a 25 min walk so maybe that lowered it a little?