"A stumbling" description inclines me to say no and chalk it up to an occasional disfluency. If you physically cannot get the words out or struggle with prolongations and repetition of words, then it may be an actual stutter. Tension would be an indication as well. If you fit this description and it has been happening over 6 months, get evaluated if you so desire. If it does not impact your life in any way, don't worry too much about it :)