my baby is two months and hasn't pooped in 18 days. I took him to his pediatrician and they said they are not worried because he's gassy still eating his stomach is soft and he's gaining weight and doesn't seem to be straining. but to me 18 days seems a little too long. is there anything I can try to do to help him go. I already tried messaging his stomach and doing bicycles. please let me know. thanks.