Constipation Concerns

How long should I let my son go without pooping before contacting our pediatrician?

UPDATE: We got a massive poop!

He’s 5.5 weeks EBF and normally poops every 1-2 hrs. He hasn’t had an actual bowel movement in almost 24 hrs now. Two “poops” yesterday afternoon that just looked like little dried poop flakes. Yesterday around 9 am he started being very fussy and my baby NEVER cries. At several points he was screaming bloody murder but seems to be in a better mood now. During the day yesterday he barely slept and was straining and grunting a lot trying to poop. He’s been doing farts more recently. He has been barely eating (went over 6 hrs overnight without feeding). He will normally BF for 15-30 minutes and has been barely going 5 before going back to sleep. Slightly concerned about dehydration as he went almost 8 hrs without peeing overnight.

I’ve tried rubbing his tummy clockwise, bicycle kicks, and a warm bath.