I'm 32+3 and have only gained 1 lb. Doc isn't worried because she's measuring right on track.
Just because you're nut gaining doesn't mean baby isn't. Your doctor is measuring your child and keeping track. I had a low weight baby which meant ultrasounds every month to make sure he gained. He was delivered 32 weeks &3 days. He's 14 months perfectly healthy but still small. Btw I gained 40 lbs so it wasn't for lack of gaining lol
I'm 25 weeks and have only gained 4lbs. Even if your not gaining doesn't mean that your baby isn't.
I had lost weight around 23 weeks and my baby has always been fine
As you go through your pregnancy your doctor will monitor your weight. If they see it's not progressing they will give you an ultrasound to see if the baby is growing and gaining pounds like it should. They usually don't start to worry about the weight until you get in your third trimester. Many girls can go without gaining so much weight and still have big healthy babies. Big belly doesn't mean healthy baby.