Katherine Heigl Shares Photo of New Baby Joshua Bishop

— -- Former "Grey's Anatomy" star Katherine Heigl and her new son Joshua Bishop were featured on the cover of People magazine this week.

Heigl, who is married to musician Josh Kelley, told People that she found out she was pregnant around the same time she was beginning to work on "Doubt," her new CBS series.

“Now we have a new normal, and I have to give myself a break in order to get used to it,” she told People.

Joshua, born Dec. 20, joins the family's two other children: Naleigh, 8, whom the couple adopted from South Korea in 2009, and Adalaide, 4, adopted from Louisiana in 2012, according to People.

Although adoption has always been important to Heigl, the 38-year-old told People that she only recently started considering becoming pregnant.

“Only when I was about 35 did I start going, ‘Well, should we consider getting pregnant?’ You don’t want the choice to be taken away from you,” she told People.

Before Heigl goes back to work next month promoting the new show, she’s enjoying her one-on-one time with Joshua.

“We’re at the point where we’re really obsessed with him,” she said. “With a newborn, you’re forced to be still … and you have this beautiful reason to do that.”