I feel stupid

My 16 week old has not had a bowel movement in about 9 days now. I called the pediatrician yesterday and they told me to give him apple juice twice a day, do the thermometer up the butt, give a warm bath and if no poop call back the next day. Well there’s only been a dime size of poop so I called back and this nurse was so unconcerned and made me feel like I was calling for no reason and it wasn’t that important. She informed me that breastfed baby’s can go 10 days without a bowel movement and it’s normal but if I’m concerned she’ll make an appointment. The appointment is for tomorrow evening and I feel like I should have not bothered.

He strains to poop once a day and screams afterwards. His belly is slightly firm but still a little squishy. He’s a normally cranky baby and has a round belly so it’s hard for me to tell if it’s more round.

My older son(2 and 1/2) also has bowel issues and he’s been taking miralax since 8months old. I want my baby’s to poop normally.