LO not pooping.

My son is 16 weeks old. He's going on 4 days without pooping. He is EBF and letting out horrific farts all day long. He never had a problem before, until last week where he went 2 days without pooping, but his poop was still loose and liquidity. He doesn't seem to be in pain, but I'm still worried. We try do tummy massages every night, tummy time after every feeding, and bicycle kicks and knees to chest all day long. Should I call the Peditrician?