You're going to stutter, and that's okay dude. Allow yourself to stutter. Don't apologize, there is no reason to apologize. You have every right to speak, just as everyone else does in the class. You can disclose though, like, 'Hi, my name is ____, as you can tell I stutter. I'm mentioning this so it's not a distraction.' Or something like that. The more you do this, the easier it gets. I'm a person who stutters by the way too.