Britney afraid of infertility

Britney Spears is apparently concerned that she may have fertility problems.

Despite having fathered two children by previous partner Shar Jackson, Kevin Federline has so far failed to impregnate the broody Britney. Kevin's previous virile successes have led the Crazy singer to belive that it may be her fertility that is lacking.

A source told Star magazine: "She's afraid it's her fault they're not pregnant yet. But Britney says if she's not pregnant by the end of January, she'll go see a fertility specialist for help. She doesn't care about the cost."