So I switched my baby's formula yesterday and she has yet to go poop. I read online that it can happen when switching formulas. How long till she will get back to normal with pooping?
It can take a few days to a week. Depends on your baby. If she doesn't go within 7 days I would call her pedi and ask if you should be concerned or what you can do to help her. I know I was giving my daughter at 2 months prune juice mixed in her formula to help her go poop but your baby is only 3 weeks so check with her pedi.