Reese Witherspoon was ''terrified'' when she got pregnant at 22.

The 'Big Little Lies' star - who has Ava, 21, and Deacon, 16, with her ex-husband Ryan Phillippe - was just starting out in her acting career when she found out she was expecting her daughter and admits it was a scary time.

She said: ''I got pregnant when I was 22 years old. And I didn't know how to balance work and motherhood. You just do it, you know? I'd made movies but I hadn't, you know, established myself as someone who could demand that it shoot close to my kids' school or, you know, I didn't have any real power, leverage within my industry. I was just like every other mom trying to figure it out - and dad out there, and partner, and grandparent who's raising a child.''

Reese has made a lot of ''sacrifices'' for her children, but insists she wouldn't have it any other way because it is ''truly worth it'' being a mom.

Speaking on The Drew Barrymore Show, she added: ''You take the food out of your mouth, the clothes off your back, the sleep out of your life. But every bit of it - every bit of that sacrifice is truly worth it because you feel like that's what makes me wake up on a Sunday. It's not movies or my job, it's my kids.''

Meanwhile, Reese previously insisted she doesn't ''stress'' about juggling her family and career even though it can be ''unpredictable'' at times.

She explained: ''It can get chaotic sometimes, but whether you're working a lot or not, life with children will always be a bit unpredictable. All mothers have a lot to deal with, and I've been doing it since I was 22 and Ava was born ... They've seen most of my films, and needs to say my daughter loves 'Legally Blonde!' But when I come home, they see me as a mother. They want me to listen to what they've been doing, help them with their homework. It's only their friends who see me as the big movie star.''