Mei Xiang, the National Zoo’s giant panda and mother of cubs Tai Shan and Bao Bao, could be expecting a third little bundle of black-and-white joy.

Scientists have detected a rise in progesterone levels indicating that the panda is either pregnant or experiencing a pseudopregnancy. Mei Xiang was artificially inseminated in April and since then scientists at the zoo have been closely tracking her progress. The panda has also been spending more time in her den, sleeping more and has started building a nest. Read more: usatoday.com