My stammer/stutter is much worse when someone asks me a question.

My stammer/stutter is much worse when someone asks me a question. Does this happen to anyone else? For instance last week I was helping hand out papers to people and called out "Theresa" and then someone asked me who and i stammered it really bad. This is a normal thing for me. Often i can get words out using a segway word or sound of some sort like instead of saying "Theresa" I would say "a Theresa or uh Theresa".