2.5 year old

2.5 year old My 2.5 year old all of a sudden just started stuttering. Woke up one day and has been for about a week now. It's not on every word or sentence, some times multiple words in a sentence sometimes just the first word. And other times not stuttering at all, some parts of the day are worse and some times there's nothing. Honestly just wondering if anyone has seen this before. Took him to the doctor and said well he's not having a stroke so just give it time. Thanks