I need a little help

So I already told my manager that I needed a few days off for vacation, but my plane will leave really early in the morning and even if I leave when I get off the day before I am worried I won't have enough time to pack and when I get back from vacation I have less than a week before I have to come home for school. So I was wondering should I call my manager and tell him I need even more time off or would it be better to wait untill I process and tell them that I need to change when I process out?

Definitely call with as much notice as you can give. They'll be more lenient with it now, as opposed to right before you need to leave. But you should try packing the a night or two before you leave, so you're ready to go. That's if you don't get any extra time off.