Officials unsure if National Zoo's giant panda is pregnant

WASHINGTON (AP) -- Officials at Washington's National Zoo say it is still too early to determine if one of the zoo's giant pandas is pregnant.

The Washington Post reports that Mei Xiang (may-SHONG) underwent a second ultrasound on Friday, but the results were inconclusive, as officials could not tell if she was pregnant or experiencing a "pseudo-pregnancy."

Zoo officials say that panda pregnancies can be difficult to detect because a female panda's hormones and behavior are the same whether she's pregnant or not.

Mei Xiang was artificially inseminated in the spring and is scheduled to have her next ultrasound on Tuesday.

This would be Mei Xiang's third cub if she is pregnant. One of her cubs lives in China, while the other, Bao Bao, is a popular resident at the National Zoo.