My son is two weeks old. He started on pro advance and was having tummy issues. We switched him to sensitive and no changes, was throwing up and not burping. The pediatrician recommended that we try Nutramigen. I read that this formula takes its time to work. It’s been 5 days and not much of an improvement. He is burping and no longer throwing up, however he is still arching his head back and getting really stiff after a feed. I’m concerned and feel bad at how uncomfortable he is. He cries a lot too due to discomfort. He has an appointment on Friday but I am calling tomorrow to see if I can get in sooner. I don’t think this formula is working for my son. Anyone have a similar experience? I know they don’t like changing formulas before two weeks but seeing my son be this uncomfortable isn’t sitting well with me. I think k will be asking the pediatrician to recommend another formula.