04/02/2016 2:37 PM AEDT | Updated 15/07/2016 12:51 PM AEST

Pregnant Paws: Giant Pandas Wang Wang And Fu Ni Waiting On Ultrasound

Getty Images / Digitally altered image

It's the celebrity couple we all want to see with a furry little baby bump -- Wang Wang and Fu Ni the resident giant pandas at Adelaide Zoo.

Fu Ni has been displaying all the hallmarks of panda pregnancy since she was artificially inseminated in September last year during her annual 36-hour window of fertility (talk about a quickie) -- but that doesn't mean she's got a black-and-white bun in the oven.

As the pair's public relations manager Alison Hassel told The Huffington Post Australia last year, a quirk to panda loving was a phantom pregnancy that came about each year regardless of whether they'd mated or not.

"Whether a giant panda is pregnant or not, they will have a phantom pregnancy that exactly mimics the hormone increase, the behavioral changes, every detail as though she was really pregnant," Hassel said.

"Also, because panda fetuses are so small, we can't see it in an ultrasound until she's two weeks away from birth."

That time is now rapidly approaching and Fu Ni has undergone several ultrasounds, but no sign of a tiny fetus yet.

Senior panda keeper Simone Davey told The Huffington Post Australia Fu Ni had recently been disinterested in ultrasounds, instead wanting to sleep all day and make nests for a potential upcoming bundle of joy.

Keepers knew Fu Ni was fertile becasue of the ways he rubbed against rocks.

“We'd been giving her about two ultrasounds a week but we haven't been able to do one for about five days now," Davie said.

""She slept for about 20 hours yesterday and she's gone off her food which tends to be a good sign that she'll be going into the birthing phase soon."

Potential dad Wang Wang.

Davie said she'd previously gone through a full phantom birth, with no baby, so they'd given her a soft toy.

"She usually nuzzles and looks after her Kong toy for a while," Davie said.

"Fu Ni has such strong maternal instincts so we hope this year she'll have a real cub."

The zoo has staff on panda watch 24 hours a day, with specialist teams ready to go in the event of a cub, or twins.

"We should know in two weeks," she said.

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