Ling-Ling, the nation's famed female giant panda, may be pregnant again after three consecutive days of mating, a zoo spokesman said Saturday.

Laboratory tests show the same hormonal pattern that was observed when Ling-Ling was pregnant last year, said zoo spokesman Mike Morgan."A lot of people are feeling positive, but no one will say for certain that Ling-Ling is pregnant," he said. "There are reservations."

If she is pregnant, she probably would give birth during the last couple of days of July or the first week of August, he said. She has given birth to four cubs at the zoo, all of which have died.

Ling-Ling and her partner, Hsing-Hsing, the star attractions at the National Zoo, mated three consecutive days during April, he said.

A sophisticated lab analysis of her urine shows the same pattern of hormonal changes as scientists observed last year when she was pregnant, which "has led a lot of people around the zoo to believe the panda is pregnant," Morgan said.

"But people familiar with the analysis are telling people that there is a lot of room for error because we have only one accurate predecessor of this year's results," he said.