To answer your question, yes.. if you get in at 11:40 that is plenty of time. BUT, with a 1 stop flight, you increase your odds of a delay. I would think they you have about 2 hours of delay margin in your plans. (meaning if your flights get you to tampa airport by 1:40 you can still make the ship. much past that and you risk traffic problems keeping you from getting to the ship on time.
Did you buy your airfare and transfer from the airport to the port via the cruiseline or by yourself. If you got cruiseline transport, they will sometimes hold the ship from departing for a little while which helps.
But as Anrea said... it is safer to fly in the night before if you can.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013