I think when you are aware you have a stutter, it needs to be actively worked on. It is unlikely to sort itself out. Until then, anything can happen. I stutter. My kid, who is 3, has been showing symptoms for a while. We are being patient, and so far, he is getting on fine. I hope he overcomes his problem. At this age and younger it is likely just a phase. This is my 3rd child. My first two had similar, shorter phases, and it sorted itself out.