U.S. pop star Britney Spears Tuesday confirmed during a surprise appearance on "Late Night with David Letterman" that she's pregnant again. Spears was in New York promoting her fragrance line and popped into New York's Ed Sullivan Theater where the Letterman show was being taped, E! Online reported. Spears, 24, brought with her 8-month-old Sean Preston, her first child with husband, Kevin Federline. The new baby is due in October, a couple of weeks after Sean Preston's first birthday.