Holy sh*t, y'all!!!

OK Magazine comes out with their cover story that Jamie Lynn Spears is pregnant and now Britney Spears is denying it!!! W-T-F ???!!!

Britney Spears told X17 XCLUSIVELY that her sister is NOT pregnant, saying "My sister is not pregnant!"

We caught up with Brit just minutes ago as she was shopping at Lisa Kline in Beverly Hills and that's what she told us!!!

Check back soon for the video and click thru to find out who else was at Lisa Kline, tailing Britney! ...