I think most of us can attest to some measure of experiencing what you describe. I also think most of us, upon reflection, will find it somewhat tricky to tease out what part of it is a general anxiousness, and what part is habitual reaction to words we've encountered so many times before. I also think we can feel like we're going to stutter regardless of whether we stutter or not. It's just that what we most focus on, in our lives, are those times where a stutter did hit. Perhaps there's some "reverse engineering" going on in our memories of such events (and our habitualization of them). Basically, to put it differently - it's rather complicated, once we get to thinking about it. But we definitely get it a lot - the sense of imminence - and sometimes we swerve to avoid it, and other times we face it head on. Stuttering is not a split-second occurrence, I don't think. It's something that keeps patterning in and out of our general speech, and we detect that in some way or other, and our reactions to it becomes patterning in itself. Perhaps we could all be better at tracking ourselves. Dunno. Seems like an arduous task. We'd have to be paying attention all the time to every little detail. But then again, we already have plenty of overhead to our speech. Maybe it's just a matter of perspective. - Am I making sense? I'm a bit tired and not quite sure how to put this in precise fashion.