Olivia Munn Says She's 'Excited' About Pregnancy, Jokes Her Bump Style Is 'Oversized Sweatpants'

Courtesy Olivia Munn

They say that pets can sense pregnancies, but Olivia Munn's two dogs, Chance and Frankie, haven't exactly caught on that she's expecting.

"My dogs will trample over my stomach," says Munn, 41, who is expecting her first child with comedian John Mulaney, 39, later this year. "I doubt they have any idea what's happening!"

But the actress, who has partnered with Petco to raise awareness about pet mental health, says she is getting ready to be a mom — and adjusting to her pregnancy thus far.

"I've been getting a lot of rest and eating the right foods," says Munn. "And my friends have been giving me some great advice. That's been keeping me sane!"

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Courtesy Olivia Munn

RELATED: Olivia Munn Urges Pet Parents to Take Their Pets' Mental Health Seriously: It's 'So Important'

In particular, "what's helped me the most is when friends tell me not to compare myself to other pregnant women," she says.

"It can be difficult as your body is changing and you feel like you look different or your body is putting on weight in different places. The consistent image that's portrayed is usually very effortless and fashionable. Mine has been a lot of oversized sweatpants!"

Now, as Munn prepares to welcome her baby (she says she and Mulaney are "still deciding" whether they'll find out the sex), family members are getting ready too.

"My mom crochets and knits a lot of stuff," says Munn. "She makes little rattles or stuffed animal toys already. This is still a new experience for me so to see my mom excited makes it feel a lot more real! I'm really excited."

For more on Olivia Munn, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here.