5 Week Old Vomiting

My baby is spitting up A LOT of milk - half the time, it is curdled already. It happens anywhere from 5-30 minutes after eating. He is breastfed and I normally pump out my initial letdown so the flow should be slow. It seems he vomits almost all of his feeding and sometimes shoots far (projectile). He doesn't seem bothered or upset when it happens. At what point should I be concerned?? If accompanied by fever or should I already take him in?

Thank you