Los Angeles, Jan 28 (IANS): Actor Jude Law says his children are his "bedrock".

The actor is father to 18-year-old son Rafferty, 13-year-old daughter Iris and 12-year-old son Rudy with his ex-wife Sadie Frost. He's also step-father to her 24-year-old son Finlay and has a five-year-old daughter Sophia with model Samantha Burke.

Also, his former girlfriend Catherine Harding is pregnant with his child.

Law's spoken out and said he cannot "believe" just how long his career has lasted but is happy with the respective careers of his children.

"There's always sensing the presence of age. I've done 57 films. Looking back, I can't believe I'm still working and maintaining my position. But I'm a happy man these days. Four children, another on the way.

"My 18-year-old's in the business. My 24-year-old, a gifted musician on piano and guitar, studies music in college. They're my bedrock," he told pagesix.com.

He's particularly stunned by his career success as he never expected to be such a big movie star.

"I remember early days in London's National Theatre. Growing up in the '1970s, I didn't dream of movies. Stage was possible. Movies, a dream. Now in the UK, I start in April filming (director Guy Ritchie's) 'Knights of the Round Table'. I play a king," the actor added.

In his new movie "Black Sea", Law plays a submarine captain and loved being able to do his own stunts.

"I loved doing my own physical stunts... In this film, I got totally caught up in the story of leadership, skill and its gritty action," he said.