The Palace made the announcement on Monday, 15th of October, as 37-year-old Meghan and Prince Harry, 34, arrived in Sydney, Australia for the start of a 16-day tour of Australia and New Zealand.
The Queen was told the exciting news the previous Friday, as she and other members of the royal household gathered for Princess Eugenie's wedding at Windsor.
Speculation about the royal pregnancy was sparked at the wedding when Meghan wore a long dark coat which covered her stomach. More rumours circulated when the Duchess was seen holding two large folders in front of her stomach as she and Prince Harry arrived in Australia for their first royal visit together.
Royal Tour
Their first official engagement will be on Tuesday. The Royal couple will continue with the tour as planned, attending more than seventy official engagements, including some in Fiji and Tonga.
Fiji and Tonga are both islands known to have reported cases of Zika virus - a disease which can cause brain abnormalities in children who contract the disease in the womb - but the couple has taken medical advice.
The Duchess has had her 12-week scan, which many people feel must be completed before public announcements are made.
Their child will be the seventh in line to the throne of the United Kingdom.
Congratulations
Prime Minister Theresa May congratulated the couple, offering her "warmest congratulations" on the happy news.
Doria Ragland - mother of the Duchess - is "very happy about this lovely news" and "looks forward to welcoming her first grandchild".
The statement said: "Their Royal Highnesses The Duke and Duchess of Sussex are very pleased to announce that The Duchess of Sussex is expecting a baby in the Spring of 2019."
They went on to thank everyone from whom they have received support since their wedding in May and said they are: "Delighted share this happy news with the public."
Earlier the Palace commented on the Royal Tour, saying: "The Duke and Duchess of Sussex are looking forward to meeting as many Australians as possible, and building an enduring relationship with the people of the country."
A highlight of the tour is expected to be the couple's attendance at the Invictus Games 2018.
The Duke of Sussex last visited Australia to launch Invictus Sydney in 2017 — which will be a major focus for The Duke and Duchess.
The Duke and Duchess sparked controversy at their wedding in May when they decided not to make it a state occasion. This meant they did not invite US President Donald Trump.
