My baby is 3 weeks old tomorrow. The past 2 weeks he's progressively started spitting up more and more after each feeding and then gets fussy to eat more as if still hungry. I try burping him but a lot of the time he doesn't. My SO is concerned he may be developing a disorder where he doesn't know when he is full (something he researched online Idk). He's been gaining weight and has consistent wet and dirty diapers. Is this amount of reflux normal or should it be of concern to talk to my doctor at his next check up?