Treated like I have Diabetes - Not Diabetic


So I've been taking Metformin for PCOS throughout my entire pregnancy. When it came time for the glucose test, I asked my doctor if I should stop taking it a few days so it wouldn't influence the results, but he told me to continue taking it because "it wouldn't hurt anything." I failed the 1 hour, but passed the 3 hour test well in the normal range. All of a sudden the doctor tells me that the Metformin probably influenced the results, and they are just going to assume I'm diabetic anyway. So I went through all of that for nothing, and now I'm going in for NST twice a week, which I think is completely unnecessary. My blood pressure and blood sugars have been perfect for the past 8 months, and my daughter's heart rate and ultrasound measurements have also been right on. There has been no cause for concern about anything until now. Has this happened to anyone else? Even if I am diabetic, wouldn't that glucose test prove it is well under control?