Jessica only gave birth to her first child, daughter Maxwell, in May but it appears she is set to expand her brood again.
It has been reported that Jessica and her fiancé Eric Johnson weren’t planning to have another baby so soon, but they are thrilled with the news.
"It definitely wasn't planned. But yes, Jessica is pregnant again," a source told Us Weekly. “She is really overjoyed!”
National Enquirer claims that the 32-year-old beauty is reluctant to confirm her baby news just yet.
“Jessica is only nine weeks into this pregnancy,” a source close to the Simpson family told the publication. “She’s trying to keep it a secret until she makes it safely through her first trimester.”
There is also speculation that Jessica is feeling anxious about having another child next year as her parents Tina and Joe are currently in the process of divorcing after being married for 34 years.
A representative for Jessica has not commented on the latest baby rumours.
The blonde star recently described motherhood as “a dream” and “absolutely amazing”.
The Hollywood couple are reportedly planning to make an "announcement" about their new arrival anytime soon.
According to friends close to the stars, it is 41-year-old actor Justin who has leaked the baby news.
"He's just so excited," a friend explained to British magazine Grazia. "It shouldn't be too long before we hear an announcement."
Justin has apparently made no secret of his desire to start a family with the 43-year-old actress. The couple have been the subject of numerous baby rumours since they became engaged in September, with their representatives repeatedly denying any such speculation.
The latest rumours have been spurred by a flurry of activity noted at the couple's new Bel Air mansion. The site owned by the couple has seen building works taking place over the last few weeks, prompting insiders to suspect that not only is a baby on its way soon, but that they could also wed on the grounds of the luxury property.
"Justin has made no secret of his desire to have a family with Jen, and they have been trying," a friend revealed. "Now it seems it's paid off and Justin hasn't been able to keep it secret."
Adding fuel to the rumour mill has also been the revelation that Jennifer turned down a recent dinner invitation to a sushi restaurant. Raw fish is something pregnant women are advised to avoid, which could explain her declining of the invite.
"[Jennifer said sushi was going to be] off the menu for a while," the friend hinted.