People are speculating that Kate Middleton is pregnant again

Kate Middleton and Prince William are on a royal tour of Pakistan. Their trip has been highly publicised - they have released behind-the-scenes photos and Kate has been honouring the late Princess Diana with her sartorial choices.

But there's something else that people have been talking about since the couple touched down in Islamabad on Monday.

It was reported earlier this week that Kate and William have taken a full entourage with them. Hello! reports that they are accompanied by their private secretaries, Simon Case and Catherine Quinn, as well as communications secretary Christian Jones, four members of the communication team, two programme coordinators, a PA, and a hairdresser.

However, the fact that they have also taken a doctor on tour with them has caused a stir.

Rebecca English, royal correspondent, tweeted: 'The couple have also, for the first time, brought with them a tour doctor. He’s a friend of William’s from his days with East Anglia Air Ambulance.'

She added that while the Queen and Prince Philip travel with a doctor regularly, it isn't something that Kate and William usually do.

So why are the Duke and Duchess of Cambridge on tour with a medic? Well, cue the pregnancy rumours.

Many royal fans on Twitter have been speculating that it means Kate could be pregnant with her fourth child. The Express is reporting that she may even be expecting twins as odds that the Duchess will give birth next year are currently 1/5, and 4/1 that she will have twins.

Alex Apati of Ladbrokes told the paper: 'Punters are seemingly confident Kate is going to give birth next year, and plenty reckon we'll soon be welcoming royal twins into the world.'

Not everyone is convinced, though, as during her pregnancies Kate has been known to suffer from hyperemesis gravidarum (acute morning sickness). Considering it was the reason that she missed Prince George's first day of school when pregnant with Prince Louis, it seems unlikely that she would be on a royal tour if she was suffering similar symptoms.

So is she or isn't she?

We'll just have to wait and see.