GD but not sure!!

Hi all, I have been diagnosed with gestational diabetes at week28, but I’m not sure if I really have it? Fasting test I measured at 5.6 (safe numbers are 5.5 and below) but the 2 tests I did after the glucose drink was clear. My gynae informed me how to control my diet, so I did try to change my bread to wholemeal, not finish my rice and eat more veg etc. But everyday I limit myself to “cheat” once a day and still drink flavoured milk, snack on chips or eat ice cream (My whole diet used to be totally carbs, processed food, snacks and flavoured drinks). So now my glucose levels are always in the 4.0-4.6 range. Just curious whether I have been wrongly diagnosed or this is the result of following a good (or rather, better) diet plan? Anyone with similar experiences do lemme know! Thanks!!