Those aren't diabetic readings
Yes, they're low but within the normal range apart from the 3.1 BUT glucose meters have a margin of error so that "3.1" could easily be a 4.2 for example
Diabetes is diagnosed from a venous blood sample for that reason.
If you're at all concerned, it's best to see a doctor to get a proper test. The blood glucose meters you can buy cannot diagnose diabetes or other glucose issues. Their purpose is to allow people with diagnosed conditions monitor them - hence the advice to see a doctor for proper tests