So my son when he feeds. Always seems to be choking or grasping for air each time he feeds. Is that normal? At ever feed!!! So I constantly burp him.. constantly. And sometimes he pulls and is kinda fussy but won't let the nipple go... seems weird .. he also sounds like he is weezing.and then I put him down on his back and he sounds like he can't breath even after I burped him.. . been going on for a while so not sure if I should call pediatrician again?