Is your stutter worse when you're asked to repeat yourself?

Is your stutter worse when you're asked to repeat yourself? My stutter comes and goes, but there's one scenario where I stutter every time. If I say something and somebody responds with "What? Or "Could you repeat that?" my brain immediately just shuts down. I can't get a single word out for the next 20 or so seconds. I have to take a deep breath and basically reset myself to say anything. It's really bizarre.