3 Week Old Hasnt Poop Since Saturday Now Thursday

Hello, everyone, I'm here because I'm feeling very overwhelmed I'm a first-time mom and I gave birth via c section on 08/08/2019 to a healthy baby girl. she was on Similac advance throughout our stay in the hospital then we switched her to the pro sensitive she was on that for a while but then her poops stopped we switched her again to the Enfamil reguline and that night produce 6 bowel movements but it seem to make her go to much so we went back to the pro sensitive powder formula. she did poop three times in one day when we came back but now she hasn't had a bowel movement since Saturday and it's now Thursday she is very cranky but eating and peeing and passing gas but it worries me she hasnt had a bowel movement yet.. PLEASE HELP