I think I'm fit to tell you this since I also stutter and literally JUST had a college interview today morning. I know it's scary, I know it's nerve wracking. I understand you 100%, I also feel a kind of relief when things like this get postponed. But listen, you need to do that interview. If you're too worried about the stutter, just let them know beforehand- say hello, nice you meet you, all the formalities, and then add "I just wanted to let you know though, I DO have a stutter, just in case I get any blocks in front of you or you hear me repeat my words a lot." Say it very casually and confidently, as if it was just a small handicap but not something you let dictate your life. This way, they'll understand that your stutter isn't something that holds you back, it's just part of who you are. This is really important. However, I don't do this anymore. I just embrace the stutter. If I stutter very badly mid-interview I just say "excuse me" and keep going, you just keep going. If they get curious about it, they'll ask, to which in that case you just calmly explain the impediment; However they hardly do so. Even though I had a few blocks during today's interview, they didn't ask me anything, they pretty much just... ignored it and kept going. So stop postponing it, stop avoiding it, just go into it headfirst. You not reaching out to them to confirm the interview date is leaving a bad impression already. Like I said earlier, do not let your stutter hold you back and drive you to lose important opportunities! I'm telling you this since I myself let many opportunities pass me by because of my stutter, but not anymore. People might think weirdly of you at first but I promise you, that's the worst case scenario. It's better to have them think "man, this guy speaks weird" or "man, this guy sure gets nervous talking to people" for a couple minutes, than to lose your place in that college altogether. Believe me when I say all this, as someone who has gone through many interviews already and has gotten positive results.