The couple, who welcomed daughter Honor in June last year, are bent on having another baby, as Alba intends to be a full-time mother.
"Jessica and Cash are working overtime to get pregnant. She and Cash are boasting that they love being parents and are determined to expand their family as soon as possible," Contactmusic quoted a source as telling the National Enquirer.
Alba had revealed in the past that she wanted more than one kid.
Meanwhile, sources have revealed that Alba has put her career on hold in a bid to try and conceive in 2009.