The UK's only female giant panda has been placed on 24-hour surveillance after the latest hormone tests indicate she could be pregnant.
Edinburgh Zoo's panda keepers are now monitoring Tian Tian around the clock.
Experts are not certain at this stage if Tian Tian is indeed pregnant but the latest hormone tests are said to show positive signs and she is now being closely watched for signs of labour such as restless behaviour and bleating.
She could give birth any time in the next two weeks, according to experts. The birth itself could last only a matter of minutes due to the small size of newborn cubs which weigh approximately 100 grams.
Iain Valentine, director of giant pandas for the Royal Zoological Society of Scotland, said: "We have now entered the window of the possible time that Tian Tian could give birth.
"Keepers are monitoring Tian Tian on a 24-hour basis. They are able to log in from their computers and phones at home just to make sure everything is ok with her, and the keeper from China has now arrived to support us. We are ready.
"About 24 hours before she gives birth she will become quite restless, start moving around, and then will sit down, her waters will break and then quite soon after that she will give birth. The birth process can be over quite quickly because the cub itself is very small. It could take minutes. It is down to the timing and her being comfortable. The cub is only 100 grams, so she doesn't have to strain too much to give birth.
"This is the point where things could go wrong. Her body could reabsorb the cub or cubs, or if she does give birth the cub could be stillborn. So this is actually the trickiest time for pandas. We will keep our fingers crossed."
Chinese panda keeper Haiping Hu, from the China Conservation and Research Centre (CCRCGP), arrived in Edinburgh on Saturday and will be on hand to assist if a cub or cubs are born during the next two weeks.
Any cub that is born at Edinburgh Zoo will be the property of the People's Republic of China and would be expected to return to China when it is two years old - the age they would naturally disperse in the wild. Once in China it will join the conservation programmes there either for breeding or reintroduction into the wild. In keeping with Chinese tradition, any cubs that are born would not be named until they are 100 days old and would only go on display on January 1 2014.