The former 'Dawson's Creek' actress is said to be "thrilled" about expecting her second child with husband Tom Cruise.
A source told Britain's The Sun newspaper: "Katie and Tom are thrilled about having another baby on the way she is glowing with happiness."
Katie - who gave birth to daughter Suri last April - showed off her growing baby bump under a loose-fitting tunic dress while in Spain over the weekend.
The 28-year-old brunette and her 44-year-old husband flew to Madrid to watch close friend David Beckham's final game for Real Madrid.
The couple - who joined the soccer star's wife Victoria in the stands - openly kissed as they watched David and his team beat Mallorca 3-1 and secure the Spanish La Liga title.
Despite her delicate state, Katie accompanied Tom, David and Victoria to the post-match victory bash, arriving at David's favourite restaurant El Chistu at 1am.
According to a waitress, David, 32, enjoyed a meal of black pudding and steak, while Tom and Katie both tucked into fish.
Victoria reportedly "only ate pineapple and strawberries, nothing else".
The celebrations carried into the early hours of the morning, with the two couples moving on to local nightclub Shabay at 5am.
The group didn't stop partying until 7.30am on Monday morning (18.07.06), when they left the club "bleary-eyed" as the "sun was coming up".
blessed on a level that I can't even wrap my mind around really."