Following news that the Duke and Duchess of Cambridge are expecting their third child, it has been widely speculated that royal baby will arrive in April 2018.

Royalists did their calculations after Prince William thanked well-wishers during a visit to Oxford on 5 September saying that they were waiting to celebrate.

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"Thank you, it's very good news. There's not much sleep going on at the moment," he said, before adding "It was a bit anxious to start with celebrating this week".

Thanks to William's throwaway comment, many people came to the conclusion that they were waiting to celebrate because she was approaching the 12-week mark−when the risk of miscarriage drops significantly.

Typically couples wait until the three-month mark before announcing they are expecting.

But that all changed on Tuesday (19 September) when Prince William dropped the biggest hint that the newest addition to the royal family could be making an entrance before April.

During a visit with Spitalfields Crypt Trust, an east London charity dealing with homelessness and addiction, Prince William reportedly told one midwife: "All the best with the midwifery, I may see you sooner than you think."

Meanwhile, speculation is still rife over what the royal baby will be called. Alice, Mary or Victoria are the most likely options if the baby is a girl. Alice, which is the bookies' favourite with 8/1 odds, has a royal heritage: it was the name of one of Queen Victoria's daughters and the Duke of Edinburgh's mother.

Should it another boy, Arthur Frederick and Philip are leading the way. Not only was Arthur (10/1), the name of the legendary 5th Century leader, it was what Queen Victoria's son and grandson were both called.

Like with both of her previous pregnancies, Kate Middleton was suffered from hyperemesis gravidarum, a severe form of morning sickness.