Shondie-It wouldn't hurt to give Carnival a call. I usually call them at 1-800-carnival or try your TA (Travel Agent). It has happened on popular cruises where you won't learn your cabin number until you arrive at the pier. When you book a gauranteed cabin it can change at any time!
Agrees with Billy, usually, but not always you can call and get your cabin 2 weeks to 10 days prior to sailing. I think someone else, and it may have been Billy once suggested to keep checking your Carnival.com registration as well.
Call em...the worst they can say is that they haven't been assigned yet. BUT, they will not tell you unless you booked with them directly. If you booked through a travel agent, the agent has to call. Just another reason to book with Carnival directly.