I agree. And at this age with tiny dogs who are measured in ounces rather than pounds, there may well have been weight gain. Vet scales are notorious for inaccurate/variable weight, he may have eaten just before his last vet vs. not yet have eaten at this most recent visit, etc. If I want a really accurate weight on a puppy I weigh in grams on my digital kitchen scale. As they get older I weigh them on my own digital scale, first by weighing myself, then putting the dog in my arms and weighing again.