Kate Middleton is reportedly four days past her due date as she waits to give birth to her second baby with husband Prince William.

According to Us Weekly, the Duchess of Cambridge was supposed to give birth on April 23. Her first boy Prince George was overdue as well when he was born on July 22, 2013.

Although multiple sources confirmed an exact due date for the 33-year-old mom, the Kensington Palace told Us Weekly, "We have never commented on or discussed a due date." It is not clear if this new baby is a boy or girl, but the Duke of Cambridge was spotted shopping for a blue outfit the day before Middleton's scheduled due date.

Once the new bundle of joy arrives, the Duke and Duchess of Cambridge will make an appearance outside of the Lindo Wing at St. Mary's Hospital in London to present the baby.

"She's doing well, in good spirits," a source said of Middleton. "Everyone is! Although it would be fair to say she's also eager for the time to come."

If the baby takes any longer, doctors may have to induce her labor within two weeks or sooner, according to The Telegraph.

"[Doctors] will probably already have been in touch with Kate and talked about which day would suit her best to go in and be induced if the baby doesn't arrive in the next couple of days," a source whose children were born at the Lindo Wing said.

Only 3 percent of babies are born on their exact due date. About two thirds of first babies arrive late and two thirds of second babies arrive early.

Pat O'Brien, a consultant obstetrician and spokesman for the Royal College of Obstetricians and Gynaecologists, says an induced labor is a very safe procedure and it is solely up to Middleton to say if she wants it done.

Meanwhile, Prince Harry may miss the birth of his niece or nephew as he flies back to Australia Monday, Yahoo! News reports.

He took a break from his attachment with the Australian Army over the weekend to make it in time for the baby's birth but the little bundle of joy is just taking its sweet little time.