I am a mild stutterer and my daughter is also a very mild stutterer also. People who stutter has different triggers and situations where they stutter. Most don't stutter when alone, but some do stutter alone. Some are triggered by anxiety, but some are not triggered by anxiety. Some do stutter in stressful environments, some don't. The reason I list all of these out is because stutterers have similarities and also many many differences. So you need to observe your child and figure out triggers. Is one environment more or less stressful than another. Compare the two environment and people he is interacting with. Observe closely at interactions he stutters in, note down who he is interacting with, the situation, his emotions during the interactions, is he feeling rushed/excited/down/worried etc. Start noting these things down in a journal or something, so you can spot differences in environment and situations. Note down when he is fluent and when he stutters. For my daughter, because her stutter was very mild and generally not noticeable, I purposely ignored it and didn't bring attention to her stuttering. I noticed her stutter immediately when she started talking at 2-3 years old. And despite my inaction, she grew out of the stutter by her teenage years. I choose the approach of inaction since the stutter was very mild and she didn't seem affected by it. Also I remember me as a kid when I did have SLPs and other help, the speech therapy didn't do anything for me except brought more attention to my disfluency. I'll still recommend that you consult a SLP who specializes in childhood stutter, but then you need to decide what next based on how much stuttering is impacting his life.