text: A spokesman for the zoo said it was hard to predict a specific date for any cub being born, and that the breeding season can last until late September.
  Tian Tian, who arrived at the zoo as part of a breeding pair with Yang Guang in 2011, was artificially inseminated earlier this year.
  The zoo said she was being closely monitored.
  This is the fifth time Tian Tian has been artificially inseminated.
  She had previously given birth to twins in China but all attempts to produce a cub at Edinburgh Zoo have failed.
  A spokesman for RZSS Edinburgh Zoo said: "Giant panda breeding is a very complicated process but we believe that Tian Tian is pregnant.
  "Although a specific date was suggested, like all babies it's hard to predict precisely and the panda breeding season can last until late September.
  "Tian Tian is being closely monitored by our expert team and we will be the first to share any news as soon as we can."
  A spokesman for animal rights campaigners OneKind said: "This poor panda cub will never be introduced to the wild and will only ever know a life in captivity.
  "To make matters worse, to produce a cub, Tian Tian has been subjected to repeated invasive procedures since coming to Edinburgh.
  "This has not been in the interest of pandas or conservation, and appears instead to be driven by the pursuit of PR and gate fees.
  "If you want to help pandas, you don't need to go and see one at a zoo. Just make a donation to conservation charities conserving pandas in their natural habit instead."
  News of the pregnancy came to light after documents were released to the Edinburgh Evening News under the Freedom of Information Act.
  If a cub was born, it would be returned to China at the age of two - mimicking natural dispersal age in the wild.
  Panda reproduction is a notoriously difficult process, with females only ovulating once a year.
  Tian Tian (Sweetie) and Yang Guang (Sunshine) are the only giant pandas living in the UK.
  They arrived on loan from China in December 2011 and are due to remain at Edinburgh Zoo for a decade.
  The zoo first announced it was in negotiations to bring a pair of giant pandas to Scotland in 2008.
  The pair were brought to the UK under a historic agreement between the UK and Chinese governments.
  Described as a gift from China, they were the first giant pandas to live in the UK for 17 years.
target: The UK's only female panda, Tian Tian, is believed to be pregnant, according to Edinburgh Zoo.