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?
Hard to say. Depends what you switched her to and how long until her body adjusts. Could be soon or a few days.
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.