Less than two weeks after giving birth to her first son, Luca, Hilary Duff is working on shedding her baby weight. We spotted her leaving a pilates class in Los Angeles yesterday wearing a black t-shirt and stretch pants.

The actress and her husband Mike Comrie welcomed their son on March 20. She announced on twitter, "We are overjoyed and feel like the luckiest parents in the world."

In the fall Duff said she was eager to get back to making music again once the baby was born. But she wants to enjoy being a mom for a few months before she gets back to work.

Check out more photos of Hilary...