I think with bf babies the growth spurt is easier as they suck in a different way, but with a bottle fed bub, maybe the sucking on the paci is enough to calm him. The best way to see if it is a growth spurt is to offer more & maybe on the night wake up & see if that works, otherwise it may be that he has developed a paci addiction & it is a prop, so it might be time to wean from that.