Kimmel, that does seem low and I've noticed the same thing. The machines at the gym always give a much higher calorie burn than Fitday. So does my Nike Plus device on my iPod. Try the option for "Race Walking" on Fitday, if you walked very briskly and worked up a sweat, it will give you a more accurate result.
In any case, keep up the good work! Like cjohnson said, it's great that you are making changes to improve your health and fitness. Don't pay any attention to vic616283. Stay motivated and keep on going! Before you know it you will be walking a mile, then 2, and so on.