I guess there is nothing to worry but you can discuss your paediatrician about choosing the right formula . Keep breastfeeding as its good for the baby

If poop is normal neednt worry. Also consult doctor for a formula change

If your baby's stool is normal and not watery then it's fine. Don't worry much..:) If the baby's poop is watery and baby is vomiting a lot then you should check with your pediatrician and switch to any fm that contains prebiotics.

Give aptamil formula milk which contains prebiotics in it which will help in improving gut health issues

It's normal Hema even u have faced this as the babies body takes time to adjust to top feed. What I suggest is continue to use this for another week and if it's doesn't work then u can try using something that has prebiotics. Prebiotics s usually help in such issues. U cud give prebiotic rich formula milk as well.