Ryan Gosling and Eva Mendes

Ryan Gosling and Eva Mendes

Eva Mendes' pregnancy was reportedly "unplanned".

The 40-year-old actress is expecting her first child with boyfriend Ryan Gosling, 33, but the baby news allegedly came as a complete shock to the couple.

A source told RadarOnline.com: "It [the baby] was completely unplanned.

"Ryan was surprised, especially because they had broken up early last year, only to get back together."

The 'Hitch' star moved into Ryan's modest home in Studio City, Los Angeles, but the property is fairly small and the pair are reportedly looking for a bigger house ready for when their new bundle of joy arrives.

The source explained: "The house is quite small, and only has two bedrooms. Eva has been looking for a bigger house to live in with Ryan once the baby is born."

Meanwhile, the pair, who have been dating since 2011, managed to keep the pregnancy a secret until recently by only telling a few close friends and family members.

An insider said previously: "[Eva] just hasn't ever wanted anyone beyond her close friends and family knowing more than they had to. And Ryan is certainly private and always has been."

The brunette beauty, who is due to give birth in October, "barely left the house" after she found out she is pregnant in a bid to keep the news underwraps.

The source added: "Their lives completely changed as soon as Eva got pregnant. They used to travel all over the place together and go on hikes with their dogs.

"Ryan has been taking care of her, picking up food and running errands. He has been very supportive about keeping things a secret."