LATEST: Britney Spears is in denial about her sister JAMIE-LYNN's pregnancy. The 16-year-old confirmed she is 12 weeks pregnant with student Casey Aldridge's baby during an interview with OK! magazine. Spears, 25, is alleged to have only found out about the baby news on Tuesday (18Dec07) via a media outlet, weeks after the rest of her family were informed at Thanksgiving (25Nov07). But hours after the news broke on Tuesday, the troubled pop star dismissed the reports. In video footage posted on TMZ.com, Spears is heard telling the paparazzi, "She's not. My sister is not pregnant." Jamie-Lynn's first baby is due in June (08).