Hi mummy.. I am at week 23 now.. My baby bump is also quite small. Most of my colleagues don't aware that I am pregnant 😅 it's okay as long as baby grows healthily. I personally feel that if you are taller and probably bigger body frame (I do not mean fat) will allow baby to have more space to grow in your body. Hence, the baby bump won't be big. I am 162cm, similar as you.