Is this considered stuttering?

Is this considered stuttering? This has happened to me all my life, but only recently i've been thinking it might be actual stuttering. Sometimes, maybe once or twice a day and usually when trying to tell a joke or being really excited about something, just before starting a certain sentence i think "oh shit here it comes..." and around the middle of the sentence the word won't come out and my neck gets tense, then after stopping and breathing it won't happen again for another day or two. Also, this has never happened to me while doing something implotant (i.e making a speech, talking in front of the class, job interview, etc.) Does this happen to anyone else?