Alah, bagus lah tu! Banyak babies memang macam tu, lactogen dengan Similac beda formula, jadi perut dia kena adjust dulu sebelum bisa poop properly. A few of my mum friends juga dapat yang sama, lagi-lagi kalau baby dapat constipation dari formula sebelumnya. Keep monitoring his poops and make sure he's still gaining weight okay, usually dalam 3-5 hari dia akan settle, tapi if it takes longer or he seems uncomfortable, check with your doctor just to be sure everything's on track.