In September (21), Mulaney confirmed he and Munn are expecting, three months after the funnyman announced he had filed for divorce from his wife Anna Marie Tendler.
"I feel good. l feel scared. I feel nervous, and I'm excited. I feel every day the feelings are just rotating through," the "X-Men: Apocalypse" star tells U.S. morning programme "Today" in a virtual appearance.
But she's worried she won't be ready for the tot's arrival.
"I just don't know how many of each item I need. Like, how many blankets does a baby need? I wish somebody could just tell me," she laughs.
But the dad-to-be is helping out however he can and Olivia's reading up on mum blogs online.
"We talk about the same stuff - 'Which rocker? What type of crib do you put the baby in? What does the baby wear?' Honestly, thank God for Instagram and Facebook and blogs because there's a lot of mums who put out such great information, and that's been a saving grace for me," she adds.
Olivia Munn is also dealing with body image issue that triggers her past insecurities as her baby bump is growing bigger.
She previously said, "It's just so hard because I will Google search 'street wear maternity', and a lot of it comes up with these gorgeous women who are super skinny, and have this little bump, and everything is effortless."