Credit: RAMEY PHOTO; JB Lacroix/ (2)

No maternity muumuus for this mama-to-be!

Hilary Duff is taking a cue from the several stylish pregnant celebs before her and is stepping up her pregnancy wardrobe. And now that the former Lizzie McGuire star is about four months along with a boy, she is sexing up her bump style with heels, skin-tight leather, and thigh-high minis.

In Beverly Hills on Monday, the 24-year-old flaunted her legs in a black mini skirt with leather panels and towering black heels. She also wore a billowy printed top and styled her hair in loose, undone waves.

PHOTOS: Baby bump hall of fame

At her book signing for Devoted in L.A. October 14, the star chose black Current/Elliott leather pants, strappy sandals and a burnt orange blouse. She topped things off with bright red lipstick.

Earlier that morning during an appearance on Extra, Duff showed some skin in mini blue cobalt shorts paired with sky-high platform sandals and an off-the-shoulder sweater.