Baby Constipated?

My 5 monther usually poops 1-3 times a day. He hasn’t pooped in three days! He doesn’t seem to be in pain or discomfort. He only farts when he tries to push and then forgets what he was doing. We were having runnier diapers before. Pediatrician saw him twice and didn’t seem concerned. Said it could have been a passing bug at the time or due to his teething saliva. His last visit, he was still gaining weight.

But now he’s pooping less. His poops are browner and blowouts more often. His farts a little smellier. Is this just his digestive system changing naturally? He’s EBF and the only thing I’ve changed is adding dairy back in to my diet after taking it out for 2 weeks (due to his previous diarrhea. Pediatrician gave the ok to start again since removing dairy didn’t change his poops). I added dairy slowly weeks ago, so I doubt that’s the issue? The only other new thing is I tried subbing non dairy probiotic yogurt (almond/coconut milk) instead of eating my usual greek yogurt. Thoughts?