Size baju baby

Salam mommys. I just entered my 3rd trimester and tga slowly beli barang baby. I was wondering about size baju baby. Agak2 week bila boleh tahu size baby kita maybe akan too big or too small? I dah beli a few size 0-3 tp nampak kecik. Risau pulak tak muat. Size 0-3 ni okay ke? #help #firstbaby