Credit:; Steven Lawton/FilmMagic

Notice anything different about Lacey Schwimmer last season on Dancing With the Stars?

The 23-year-old pro -- who competed during this fall's season 13 with Chaz Bono -- recently went under the knife for a hush-hush boob job.

A source close to the reality star tells Us Weekly that Schwimmer got plastic surgery to enhance her bust two cup sizes, from a B to a D.

"Lacey's told friends she got a boob job. She'd wanted one for a while so she went ahead and did it," the source tells Us.

Having long faced criticism over her figure, Schwimmer -- who said she was "happy" to have an athletic build instead of a model shape -- couldn't be more thrilled with her latest look.

Says the insider: "She loves the results and she's proud of her new shape."