Kate Middleton Due Date Mystery

July 13. That's supposed to be the Duchess Kate Middleton's due date. Only it's not.

After the rumored due date was first published by the Daily Mail back in May, it somehow became an unconfirmed fact. We figured we better call the Palace just to make sure.

"We have said July and the Duchess said mid-July," a spokesperson for Kensington Palace told Yahoo! Shine on Wednesday. "The media decided it was July 13. We never confirmed an exact date."

So there you have it.

The source for the supposed due date was a "friend" of the royal couple. According to the Daily Mail, the "friend" who attended a barbecue hosted by the royal family revealed: "They were all discussing the fact that Kate's baby is due to be born on July 13.'"

Other major media outlets have picked up on this date since then.

Journalists, photographers, bloggers and other royal family fans have become fixated on July 13. The impact will be huge. For one, July 13 falls smack in the middle of the Four Day Coronation Festival in England, which marks when Queen Elizabeth II was crowned in 1953. Royal gamblers are also majorly invested (literally). According to Rupert Adams, a spokesperson for the online betting website William Hill, over $26,000 in bets have been placed on the royal baby's sex, hair color and name.  Manufacturers are also be on their toes for a post-birth production boom since the sex of the baby is unknown, and merchandise designs will depend on the title of the little prince or princess.

The frustration of not knowing has led some to some far-fetched speculation. On Tuesday, the Telegraph reported of rumors circling that "the Duchess may be due earlier" but has "kept the true date a secret, much like Princess Diana." It's true that Prince William was born twenty-one days before his projected due date, but don't blame the Palace.

As Middleton herself has said, "Babies have their own agenda." According to Parents magazine, only 5% of women give birth when they think they will. And as many of you know, a due date is merely an estimation or prediction, not a declaration.

So if you're expecting the royal birth plan to fall in line with your own agenda, a gentle reminder: it's not up to you.