Scientists at the park, commonly known as the National Zoo, conducted tests on the female panda to determine if she was pregnant, but the animal's declined urinary progesterone indicated the end of a false pregnancy, The Washington Post said Wednesday.
Zoo researchers confirmed the diagnosis through ultrasound exams Tuesday that revealed no visible fetuses in Mei Xiang.
The false pregnancy comes after the 250-pound giant panda was artificially inseminated on Jan. 17. Giant pandas are endangered worldwide with more than 200 currently in captivity and nearly 1,600 free in the wild.
The Post said while Mei Xiang had been exhibiting certain unspecified behaviors typically associated with prenatal activity, zoo officials remained cautious up through the confirmation of the false pregnancy. The false pregnancy was the third for Mei Xiang in as many years.