I do it at the beginning of my speech. Repetition, block and grimacing. All of them. It's because my stutter is usually blocks and sometimes grimacing. Including repetition, block and grimacing when saying "hello, my name is X" is a short way for me to express "I have a stutter. I get blocks. Blocks are involuntary pauses. Grimacing is my secondary behavior, which is semi-voluntary and is not an expression of disapproval of you."