Its so nuanced, it seems like it could trigger from a certain situation or word that reminds us we can stutter and our memories are attached to feelings so the body starts sending signals and changing to how we were in our memory, that's why ptsd is so scary even when technically we aren't there anymore, and can bring up the stutter just from someone asking us to repeat something we just said without a second thought maybe because we remember we can stutter on it and there it goes.  So I think it depends how comfortable you are and how good of a memory you have of it and so on.   We tend to assume the worst and it's better to just assume the best, no one really cares and are worried over themselves so if we're still smiling after, that's all the signal they need to vibe with us.  I don't even dwell on it.  So, though anything can be embarrassing, you're fine and everyone moves on as happily as you do, people remember feelings over things we say anyway.