^^they will give you a lot of hassle if all your forms aren't in. You can still register for classes, I think, but your status will be temporarily put on hold. Just be sure to take a look at the list first--there's a hefty list of shots. The office is also a zoo on the first day of orientation, so I would avoid it if I could (wouldn't you rather spend the time moving in or relaxing or hanging out with your new classmates? than waiting in aggrevating lines?) But if push comes to shove, I think the office also offers shots (I remember a lot of kids being lined up to complete their missing shots).
Make sure you make (and BRING!) copies of all the med forms with you. Last year, even though I had sent everything in, they told me that some files were "incomplete" (duh...because they lost it?) Luckily, I expected their incompetancy so I pulled out my copies right there. The nurse then tried to take and keep the copies I had made, until I politely pointed out "um, can you make copies of those? Those are my copies" (only because I still didn't trust them...whatif they also lose my copies?)