Watch Out Royal Baby, Mei Xiang the Panda in Washington, DC, Could Be Pregnant

Zookeepers at Washington D.C.'s National Zoo are abuzz with excitement as they wait to see if Mei Xiang the panda is pregnant. She's experiencing a rise in urinary progesterone, which scientists say, could mean she's pregnant. They've also seen her building a nest. Ultrasound images are inconclusive - Panda fetuses don't develop until the final weeks of gestation. Visitors are thrilled with the news.