Kristin Cavallari is very determined to stay fit during her third pregnancy. On Tuesday, the former reality star shared a photograph of herself working out, showing her baby bump and favorite fitness move. The 28-year-old shared with other expecting mothers, her favorite workout routines while pregnant, on her own mobile app. Besides showing off exercise options, Jay Cutler's wife has been documenting her pregnancy style on social media, and in a recent picture she posted, she wrote, "Dressing for the bump." In May, Cavallari shared the news that her and Cutler were expanding their family. Earlier this month, she revealed that her two other sons, Camden Jack, 2, and Jaxon Wyatt, 1, were getting a little sister.