Josh Duhamel already wants another baby.

The 'Safe Haven' star's wife Fergie is set to give birth to their first son next month and he hopes she will want to expand their family even further because she has enjoyed her pregnancy so much.

The 40-year-old actor told EOnline.com: ''[She's] unbelievable. The girl is so impressive.

''You never know how it's going to go. Some girls have a tougher time, some a little easier. Because it's a boy, it's been a really lucky pregnancy in a lot of ways. She's been happy, in good spirits, she looks great. Even at 8 and 3/4 months, she's still in great spirits and looking beautiful. And that just means that she's going to want another one, which is good for me.''

The Black Eyed Peas star, 38, officially changed her name from Stacy Ann Ferguson to Fergie Duhamel last week and Josh said: ''I think it's very sweet. I think it's a really sweet gesture for her to do that. I didn't ask her to do it, she just did it and it says a lot. She's an amazing girl.''

Josh and Fergie confirmed they were having a baby boy last month and although they have decided on a name, they are planning to keep it a secret until he arrives.

He said: ''I grew up in North Dakota so we were going to name it North but Kim and Kanye took that.

''It's a fairly traditional name but you don't hear it very often. It means a lot to both of us and part of it is a family name. We're not telling anybody because we don't want to hear it. No matter what you chose, people are going to have their comments.''