Britney Spears and husband Kevin Federline are expecting their second child together

Britney Spears and husband Kevin Federline are expecting their second child together, Spears told David Letterman during a surprise visit to his show on Tuesday.

Spears's announcement, first reported by Access Hollywood, last week , was confirmed by the singer's rep. " A source close to Britney Spears's family" confirmed to Access Hollywood that Britney Spears was five months pregnant.

The singer was spotted at baby boutique to the stars, Petit Tresor recently. The store is a favorite for celebrities like Katie Holmes, Demi Moore and Jennifer Lopez.

A witness to Spears’s shopping spree told the Scoop, “She wasn’t really buying that much. She just picked out a few things. She doesn’t yet know whether it will be a boy or a girl, but she’s really hoping for a girl this time. She’d love to buy her new baby pretty, frilly things. She wasn’t as excited this time around. She was pleasant, but seemed more sedate. She wasn’t as bubbly.�

Earlier this month, Britney Spears’ spokesperson denied reports that Britney was expecting her second child with husband Kevin Federline.... after the star was spotted drinking alcohol at Federline’s birthday celebrations in Las Vegas

Her representative stated, "Britney's not pregnant, and if she were, she wouldn't drink."

However, unconfirmed reports claimed at the time that Federline had to rush Spears to Santa Monica UCLA Medical Center, after the singer suffered stomach cramps, reports Entertainment wise UK.

According to Us Weekly in their new issue. "Britney is 100 percent pregnant again with her second child."

Spears, reportedly couldn't hide her pregnancy when she showed up poolside at Caesar’s Palace in Las Vegas this weekend, sporting a red bikini and a serious bump.

When Spears' doctor confirmed her pregnancy she "cried her eyeballs out," says Us Weekly

Spears, 24, and Federline, 28, already have a son, Sean Preston, who was born in September of last year. The pop star, who has been on an extended hiatus for nearly two years, calls motherhood "such an intense experience."

Kevin has a daughter Kori, 3, and a 21-month-old son Caleb from his previous relationship with Shar Jackson.

Spears wed Federline in September 2004, and the pair began talking about starting a family soon after. "I can see myself as a mom. Next year at 23, I am so there," she told PEOPLE shortly after the wedding. Just four days short of the couple's first wedding anniversary, she had accomplished that goal.