The Always Sunny in Philadelphia star, who is married to series creator Rob McElhenney, said that she has had a very "easy" pregnancy so far and hope that the luck continues until the birth in August.
Olson told People magazine: "I haven't been nauseous at all, so far - I hate to jinx it. I feel pretty normal except I can feel something moving inside of me.
"Rob wanted to find out the sex. I wanted to wait. But as soon as we decided we were going to, I couldn't wait to find out.
"You're just happy that all of his little fingers and toes are there. And he's really handsome, I'll tell you that much. We've seen pictures!"
Describing McElhenney as an "awesome" support, Olson added: "We've been together for many years now and we've been talking about having kids for quite a while. I'm certainly ready."
