All week my 3 month old has been a terror to feed from my left breast. Whenever I try to lay him down he starts screaming, which is strange because he rarely cries normally. I've ended up having to feed him sitting up, straddling my leg (not easy, since he can't sit up on his own yet). Once he gets eating, I can lie him down, no problem. What could be the problem? I thought maybe some pain on his right side (arm, ear, jaw?) but then, he will go down once he's calmed down. Nothing scary or traumatising has happened that would cause this (that I can think of, anyway). Any ideas?