Britain's only female giant panda has conceived, but it could be some time before experts know if she is pregnant, according to keepers.
Tian Tian was artificially inseminated earlier this year but keepers at Edinburgh Zoo said implantation, when a fertilised egg attaches itself to the uterus, has not yet occurred.
Iain Valentine, director of giant pandas for the Royal Zoological Society of Scotland, said: "Scientific data does suggest Tian Tian has conceived, however this is not pregnancy.
"Giant panda pregnancies are extremely complex. Pregnancy begins when implantation takes place and this has not yet occurred.
"There are many hurdles to get through yet, so we would request that people do not get too excited at this very early stage."
A fertilised giant panda egg will not immediately implant on the mother's uterine wall, but instead is said to "float" around in her reproductive tract for varying lengths of time.
The panda was artificially inseminated for the third time in March.
Semen from Edinburgh's other panda, Yang Guang, was used in the procedure carried out by a team of three vets at the zoo, alongside a panda expert from China.
Keepers have inseminated Tian Tian on two previous occasions but she has so far failed to produce a cub.
Tian Tian (Sweetie) and Yang Guang (Sunshine) are the first giant pandas to live in the UK for 17 years.
The animals arrived on loan from China in December 2011.
There were hopes that a panda cub would be born last year when Tian Tian became pregnant following insemination.
However, vets who closely monitored her believe she may have reabsorbed the foetus.
Panda reproduction is a notoriously tricky process, with females only ovulating once a year.
The gestation period is typically five months and one or two cubs are usually born.