weight gain

I am 30 wks today & I have only gained like 16pounds.. Someone at work said I look like I stopped growing I'm all belly I'm due the 25th of January so I'm sure I will gain more.. I go to a class thing every 2wks so I asked the doctor last class she said just fit more snacks in but I eat 3meals & snack a decent amount so idk.. anyone else feel like they're not gaining good? Baby is moving like crazy still & awfully strong..