Elevated BMI

So I went to my OB to go over my 20 week scan and this is my 3rd pregnancy. I’ve never had any issues before and have always been overweight. Well they said this boy is BIG and made me do an early diabetic screen and have to get another ultrasound in a month. Doc said it’s most likely genes and to not worry. My husband is tall and big. My first was almost 10 lbs and I didn’t have to do this. Is this new? Lol Anyways the reading dr of my ultrasound even said to have me deliver early, which my doc said we need to do. I’m hoping I don’t have diabetes. All I do is eat candy and sweets 😖