bby chockimg milk

Bby is currently 12days old , im a ftm and i asked hub to make formula milk for bby. And.. So i was feeding bby formula and realised that he was 'chocking' milk but i just let bby sit up instead of half - lying down position thinking that baby was just damn thirsty. As he is the type (that i realised) that suck very fast , till he was literally chocking on his milk. I was devastated, bby wasnt crying but was coughing and then just smiled. I started crying when i realised that the teat my husb prepare fir the feed was #2 instead of #1. I felt so hurtful that i was careless enough not to check and hub was just so clueless and hadnt have any reaction when bby was chocking.