Drew Barrymore with fiance Will Kopelman in Los Angeles on May 2, 2012. Credit: Bruja/Juan Sharma/PacificCoastNews.com

Casual Drew!

Drew Barrymore and her fiance Will Kopelman went for a stroll in Los Angeles Wednesday while the star displayed her pregnancy curves.

The actress, who has yet to confirm her and Kopelman's first pregnancy herself, wore a clingy ivory sweater over a white T-shirt, both of which hugged her growing baby bump. She also sported baggy boyfriend jeans with a hole in the knee and brown heeled booties.

On Monday, the Big Miracle star, 37, embraced her new mommy-to-be curves on the set of a photo shoot in San Marino, Calif. Dressed in a breezy, pink long-sleeve dress, the number's black belt accentuated her growing stomach.

"She is so thrilled to be expecting," a source told the latest Us Weekly of Barrymore. As she prepares for impending motherhood, the star is also just as hard at work planning her June walk down the aisle.

According to a source, the mom-to-be will don Chanel for her ceremony, to be held at her Montecito, Calif., home. (Her future father-in-law, Arie Kopelman, is the former CEO of the fashion house.)

Barrymore -- who began dating her man in January 2011 and accepted Kopelman's proposal a year later -- is in full-tilt wedding planning mode