My 4 year old son is stuttering. What should I do?

My 4 year old son is stuttering. What should I do? In the case of my 4 year old, I noticed his stuttering as soon as he started talking full sentences at about 2 years old. I kept monitoring for the past couple of years hoping it's a childhood thing but it appears to be a genetics as his uncle (my husband's brother) also stutters. I'm completely unfamiliar with what to do and where to start so anything helps! Those of you who remember your childhood, what did your parents do that helped? What do you wish had happened when you were younger? I'm fully committed to therapy or anything else and absolutely terrified that my son will get bullied at school :( I've also asked my pediatrician but she says we should wait. She thinks it's a childhood thing but I don't want to lose time in case it's not (and I think it's not).