Jessica Simpson's steady weight-loss journey has reportedly been derailed.

The Fashion Star mentor, who has shed 70 pounds since her daughter Maxwell Drew was born on May 1 thanks to consistent exercise and a $4 million endorsement deal with Weight Watchers, is expecting another baby with fiance Eric Johnson, Us Weekly reported in its new issue Wednesday. 

"It definitely wasn't planned," a source told Us of the pregnancy, which only a few people close to Simpson reportedly know about. "But yes, Jessica is pregnant again."

The news comes only seven months after Maxwell Drew was welcomed into the world at nine pounds and 13 ounces via C-section. Simpson and Johnson reportedly believe being parents has been the "greatest experience" of their lives and Simpson gushes that "motherhood is a dream."

A representative for Simpson, who previously starred in VH1's The Price of Beauty and MTV's Newlyweds reality series, declined comment.

Simpson, 32, and Johnson, a 33-year-old retired former NFL player, got engaged in late 2010. According to Us, the couple said in September they had intended to get married in 2012 but parenthood became too time consuming for them to engage in wedding planning. Now that Simpson is pregnant again, their wedding will most likely be postponed again.

"It's not something she's even looked into," an insider told the magazine.