Your pediatrician is wrong. I can't say that in a nicer way. Preschool therapy is usually quite effective. AND the fact that your concerned about it warrants therapy. A SLP might not see your child for long but it at least warrants an eval and a consult. And, not all preschoolers who stutter need therapy. Certainly many children "naturally" recover. But, it's all about risk factors. More risk factors = higher chance at persistence. more risk factors also mean more therapy. And, the therapy isn't just about speech. Much of preschool stuttering therapy targets family interactions, i.e. making sure the child has space to talk, isn't rushed, has good strategies/reactions for when they do get stuck, etc. PM me is you need to. I can say more. If you PM me your location, I can also perhaps find a good SLP for you to contact.