No baby belly at 18weeks 2days

Hi mummies! How do your baby belly look at this gestation? This is my 4th baby and the smallest among all. Went for Oscar scan on 12weeks & everything is okay for baby. I feel my baby first movement like strong kicks is on my 17weeks. I was 47kg before,160cm. Now around 53-54kg. I used to gain 25kg for each pregnancy. Anyone encounter the same thing as me? Nobody noticed or even believe I am pregnant at my workplace. They thought I only gained some weight during CB period. I don’t mind not having a visible baby belly as Long as my baby is normal and healthy! Haha