Tian Tian was artificially inseminated in April after she and her partner, Yang Guang, failed to mate naturally.
However, nothing is “black and white” in the panda world. Officials at Edinburgh Zoo said while tests indicate she has conceived, it is not yet known if she is pregnant, as the embryo is not implanted into the womb immediately in pandas.
They said if everything goes well, Tian Tian could become pregnant in 20 to 30 days and give birth at the end of August.
Iain Valentine, director of giant pandas for the Royal Zoological Society of Scotland, said Tian Tian was being closely watched for signs of pregnancy.
He said: “It is still way too early to make any definitive predictions. Tests do indicate that Tian Tian has conceived, but not that she is pregnant.
“Pandas practise delayed implantation so at this stage the embryo is still in diapause, or rest, so technically pregnancy has not happened yet.
“There are many more significant developments still to take place. Timings are all approximate but we have just seen a secondary rise in progesterone in early July, so if all remains on track, in 20 to 30 days pregnancy will commence.
“After this, if successful, Tian Tian would give birth roughly around late August. As you can see, there is a long way to go yet, so we would urge everyone not to get too excited at this stage.
“Tian Tian is in great health, very relaxed, at a great weight and eating well, and keepers continue to monitor her.”
Hopes of a pregnancy follow last year’s disappointment when the pair did not mate. Although Tian Tian was artificially inseminated, she lost her foetus.
Tian Tian and Yang Guang are the first giant pandas to live in the UK for 17 years.
Scottish bookmakers McBookie.com last night slashed the odds of an Edinburgh Zoo panda from 3/1 to 6/4.
Paul Petrie, McBookie.com spokesman, said: “There is still a long way to go but this is really positive news and we are now offering 6/4 that a baby panda will successfully be born. This time last year we were offering 14/1, so the odds are clearly a lot better in 2014.”
But John Robins, secretary of Dumbarton-based Animal Concern, which campaigns for animal welfare, said pandas were mostly dying out in the wild and dismissed news of a possible pregnancy as a “publicity stunt”.
“This is just the latest step in an economic and political panda pantomime being played out by Edinburgh Zoo,” he said.
“They obviously want to attract people during the school holidays, but it’s a great pity they are not telling the paying public the truth, which is that one of the main reasons pandas are dying out in the wild is because the Chinese government is allowing development to encroach on their habitat.”
Manuela Calchini, of Visit-Scotland, said: “Visitor numbers at Edinburgh Zoo rocketed following the arrival of Tian Tian and Yang Guang, and the world has continued to follow their story.
“If Tian Tian does become pregnant, the excitement will intensify and images of Edinburgh Zoo will be seen across the world. This will generate a real buzz not only around the zoo, but also around Edinburgh and Scotland as a whole.”
The animals, now both aged ten, arrived from China in
December 2011 and will remain at the zoo for a decade.
In April 2012, the Advertising Standards Authority criticised the Scottish Government for a series of ads it produced claiming the pandas were a “gift” demonstrating the close relationship between China and Scotland.
The ASA ruled they were in fact part of a “commercial arrangement” between the zoo and the Communist authorities.