First, if you aren't already doing it, do some kind of cardio workouts several times a week. That helps you acquire and maintain some good muscle tone all over, and burns calories to keep your fat content down. You can jog, swim, do the machines, do active sports, or whatever works for you, preferably something fun enough so you won't shirk it. Second, don't expect to have a boy tummy. You're a girl, and part of it is having a womb that creates a sexy bulge to your lower abdomen. Celebrate it, flaunt it, love it, show it off, use it to entice the special man in your life. And third, ditch the magazines. Real women aren't anorexic and don't have their photos airbrushed to conform to some swishy editor's idea of what looks good.