Ay, normal lang yan mama! Dark green poop (that's meconium-like or transitional stool) is super common sa formula babies around that age, especially if the formula agrees with them, a few of my mum friends had the same thing and their babies were perfectly fine. But if the poop is consistently very dark green, looks tar-like, or your baby seems uncomfortable or constipated, better check with your doctor just to be safe, okay? Otherwise relax, every baby's poop colour changes all the time!