Not gaining weight

Since his first birthday LO was 26 lb (now he is 16 months) and his weight isn’t going up.When we went in April for regular check up he was 26.2 lb I think.But now I think he is loosing weight when I put him on home scale shows 23 lb 😬😱.

He have breakfast lunch dinner snacks(fruit,those eggo pancakes,cheese puffs,yogurt)

He eats same food as us.

But when he is full he will move his head when he doesn’t want anymore.

Am I doing something wrong?

I told my concerns to his pediatrician and he wasn’t worried because by his words his weight isn’t going above lines on chart and he is doing good and his height is also good for his weight.

He is born at big baby so only pediatrician worry was when he was smaller that he will be overweight t (he was gaining weight faster than now).

Also to add by his weight he is 90 th percentile,height 84th percentile and BMI 83 rd percentile.