Britney Spears: Not on Drugs!

Last night, authorities said that Britney Spears appeared to be “under the influence of an unknown substance.”

Life & Style is reporting that Brit‘s blood tests at Cedars-Sinai Medical Center came back negative.

“Her blood test just came back, and, thank God, it was clean. There are no traces of drugs or alcohol of any kind,” a source says.

Brit‘s father, Jamie, and her ex, K-Fed – as well as both of her sons Sean Preston and Jayden James – were spotted at the hospital with Britney.

WHAT DO YOU THINK is wrong with Britney if she’s not on drugs?