Weight gain or lack there of??

Christy
So I am 29 weeks and have only gained 2 pounds. I started off at 232 and now I'm 234 I find it odd but my dr thinks it's good since I started out so big. I am concerned bc I want him to be healthy but you can't even tell I'm pregnant. Has this happened to anyone else? I have to schedule an ultrasound next week so I am hoping once I get that they can tell me if he is growing at a good pace even without the weight gain.