Jessica Simpson has finally confirmed the obvious -- that she is pregnant with her first child.

"It's True! I am going to be a mummy!" Simpson announced in a website posting tweeted from her Twitter account on Monday afternoon.

Reports that the 31-year-old, who has sported in increasingly prominent baby bump recently, was pregnant had circulated since late summer.

Late last month, In Touch Weekly reported that Simpson -- who will serve as a judge on NBC's upcoming Fashion Star reality competition and previously starred in VH1's The Price of Beauty and MTV's Newlyweds reality series -- had learned she was pregnant on September 12.

"She took a home pregnancy test," a friend told the magazine. "And when it came back positive, she called a close friend and asked her to buy several more tests and rush them over."

Simpson reportedly took "nearly a dozen" additional home pregnancy tests before she shared the news with fiance Eric Johnson and had the pregnancy confirmed by a doctor a week later.

According to In Touch, the pregnancy was unplanned and the result of Simpson's decision to stop using birth control shortly after she and Johnson, a retired former NFL player, got engaged late last year.