Pregnancy weight gain

First time mom here and I’m curious what the “normal” amount of weight gain is during pregnancy. I started at 109 pounds and had my 28week appointment today and now weigh 127, I’ve only gained 6 pounds since my appointment last month. The problem is my ob acted like that’s a very bad number, pretty much called me fat and told me to lay off the carbs 😅 from my point of view I don’t think I’ve gained too much weight considering I’m literally growing a baby but she acted like I was on my way to obesity and that didn’t feel great