Katherine Heigl is positively glowing!

In a new interview, the 37-year-old actress gushed about her first pregnancy — and admitted it's becoming difficult to hide her growing baby bump while filming her latest TV show, Doubt!

“We’re working really hard to try to hide [my pregnancy], and it’s a challenge,” the former Grey's Anatomy star recently told People. “Because every day my body changes a little bit more."

“We started out with really high hopes of [my character wearing] fitted, pencil skirts and those really great Victoria Beckham dresses, and that became impossible pretty quickly,” she added.

MUST SEE: Grey's Anatomy Star Caterina Scorsone is Pregnant With Baby No. 2!

Katherine previously announced she and her husband, musician Josh Kelley, 36, are expecting their first biological child — a boy! — in late June. The couple, who tied the knot in 2007, are already parents to two adopted daughters, Naleigh, 7, and Adelaide, 4.