The countdown is underway for Prince William and Duchess Kate's second baby
, as their little prince or princess could arrive any minute now and ET's royal insider Katie Nicholl has been gathering details outside St. Mary's Hospital in London.
Kate will give birth in the Lindo Wing at the hospital -- the same place where she delivered Prince George in 2013. She will also be attended by the same team of doctors.
While many took Kate's pink coat during her last public engagement as a sign that her baby will be a girl, Katie has learned that William and Kate do not know the gender of the baby. What they do know is that the child will be fourth in line for the throne.
"That means Prince Harry gets bumped down to fifth place," Katie says.
After the delivery, William and Kate are expected to carry their newborn out of the hospital and pose for the world’s press just as they did for Prince George.
What's shaping up differently for this pregnancy as opposed to the first is that last time, Kate was hospitalized for extreme morning sickness. During her hospitalization a pair of Australian deejays placed a prank phone call to the hospital, imitating Queen Elizabeth II and Prince Charles.
Similar to Prince George's birth, bookmakers are speculating on most likely baby names. For a girl, Victoria, Alice and Charlotte seem to be favorites.
Prince William is already on paternity leave, as he completed his air ambulance training early.
What's more, the second royal baby would likely celebrate his or her birthday within the same time frame as the Queen! Her Royal Highness turned 89 on Tuesday.