You may do the best and still not be correct. You may have looked everywhere, you may still miss the problem. And then sweet little Johnny shall squirt himself all over you. There you go, Mr and Mrs Wisdom !
Pediatricians are as woefully inadequate as any young parent.It is just that they have had a bit more than your experience and have learnt a lot from your woes. And, the most, from the owners of the wiggling tiny toes.