Don't be ashamed that you are a stutterer. I know how it feels inside; you always have this thought of people will be judging or ridicule us because we stutter. Tell your professor that you have a stutter disability. Few years ago, I have mentioned to some of my friends that I'm a stutterer and that I'm doing some treatment and they never judged me and we're supportive. Last time, I had a bad stutter and I told the person that i was talking to that I'm a stutterer.