PLEASE! 20 month old with PECTUS EXCAVATUM!!

PLEASE! All doctors read this! I have a 20 month old son with Pectus Excavatum. I am seriously worried about my baby. For one thing I took him over a year ago and expressed my concerned about his chest moving inward when he would inhale. I was told that this is normal and he would grow out of it. So a couple of months ago I told them he has not grown out of it and his chest is sucken in and in moves inward when he inhales. They diagnosed him with Pectus Excavatum. Here is my concern, every patient with this deformity doesnt have the movement of the chest/sternum like he does. The only thing they did with him were x-rays. Nothing more. Im not satisfied with this and Im worried for his life, everyday I pray that God will keep my child safe. Please I need a doctor to give me some advice here. Im stressing out! Is his chest moving inward a big cause for concern?? They said the x-rays shows it isnt putting pressure on his heart or lungs, but how can they know that his heart isnt in distress without proper test....I really need some help here, Im begging any medical professional that has answers to please help me with this!