Jessica Biel is reportedly ready to start trying for a baby with fianc Justin Timberlake before they've even walked down the aisle.

The couple got engaged over the Christmas holidays and are said to be full speed ahead with their wedding plans.

Star magazine claims that the 30-year-old actress is so excited about starting a family with the Sexy Back singer that she sees no reason to wait.

"Jessica hasn't been shy about telling everyone that she and Justin are already trying for a baby," a source told the publication.

"She even made jokes about finding a wedding dress with room because she's hoping to have a baby bump on the big day."

The couple have been together for six years and have faced plenty of challenges, but are now said to be very much on the same page of their life plan.

"She's been feeling her clock ticking for years and has known all along that she wanted Justin to be the father of her children," the insider added.

"And he definitely wants a family too. In fact, he's finally starting to treat her the way she deserves to be treated. And that's given her the confidence to tell him what she wants which includes a baby."