I feel you will be ok since Carnival is aware and all.
I have found it is so much nicer to fly in the day before,I book with Orbitz,and get a Hotel close to the Ships pier. We normally get on the ship between 11am and 12am eat and lounge by the pool with a "fun ship" Its like having a extra day at sea. You must remember to put your swim suite in you carry on, as your luggage wont be available for a while
