You need to first check what type of plane. Small regional jets have a very small overhead space. Just barely big enough for a lap top case. The underseat area is also very small on the regionals.
Some airlines offer an advance boarding for a fee. Southwest is one that does it , for $12 or maybe $15.oo each way you can advance board , but you must pay this ahead of the flight. If you are flying this airline pay this fee now , if you purchased your ticket to secure the advance boarding. Do note that it will not fit in most overheads in the upright position, and you will most likely have to lay it on its side.
Last edited by Lori S; 04-15-2014 at 07:40 PM.