A fasting test is only necessary when testing triglycerides. Personally I do not pay much heed to a fasting test of blood sugars. The reason is that if you don't eat, your liver will provide sugar in the form of a liver dump and this will raise the reading. Testing a liver dump is not that helpful and having it formally tested at the surgery just means waiting until the appointment time which can result in a reading being taken hours after you are up and about and also be meaningless.
Put your readings of 4.7 and 6 into that context and you have nothing to worry about.
I prefer to test before a meal and two hours after it.