so much spit up

Z
My baby boy is almost 3 weeks old and he's started spitting up all the time. He spits up a little during feedings and then after feeding within 20-30 minutes usually. He just spit up 4 times in the past hour which is a record. He is breastfed and I feed him in an up right position and keep him upright after feedings. I don't know what else to do! And his feeding schedule seems to be off today too. Any suggestions?