What can I do for a constipated 12 week old? I’ve been bicycling his legs and massaging his tummy but it hasn’t helped 😩

Rayne, that's good! Mine was using the potty by 10 months because when she'd start straining I'd just set her on it (still with hands under arms 🙄😅) and she'd go right away!
I had to do apple juice for my dd when she was that age because she would get constipated so bad from formula. 1 oz. Usually did the trick
I finally got him to go by doing what you said! Thank you
My last baby would only poop if I'd hold her under her arms and sort of let her butt hang between my knees in a sitting position. I'd pull the bottom of her diaper away from her butt before positioning her.