In recent years the sizzling chemistry between the Time Lord and his assistant has become as much a part of Doctor Who as cool gadgets and the famous Tardis.
So pictures of Amy Pond – played by actress Karen Gillan – looking heavily pregnant are sure to cause quite a stir amongst fans of the long-running series.
In an upcoming instalment of the show, titled Amy's Choice, the doctor's sidekick is seen looking expectant and thoroughly fed up.
The episode is set five years in the future and also stars Amy's fiancé Rory, who made an appearance in the first episode of the series.
Bosses are keeping tight-lipped about the pregnancy – in particular whether the father of the child is the Doctor or Rory – but they are promising that fans will get an insight into how it occurred.
One source has said of the episode: "Viewers will have to wait and see how the pregnancy came about, but as always with Doctor Who, things are not always as they appear."
Sure to throw the question of Amy's pregnancy up into the air will be her first kiss with the Doctor.
On Saturday, the couple lock lips for the first time, although it remains a mystery as to why and how it takes place.
Meanwhile, fans will have to wait until May 15 to find out about Amy's baby bump. That show will also see the Doctor, played by Matt Smith, driving a camper van and his Tardis parking in a flower bed.