Britney Spears' Femme Fatale 'Not Done,' Dr. Luke Says 'We're in the middle of it right now,' producer says of March 15 release.

With a little more than five weeks left until the release of Femme Fatale, it seems that Britney Spears is still working alongside the album's executive producers, Dr. Luke and Max Martin, to put the finishing touches on the album.

"We're in the middle of it right now. It's a little bit fluid right now. I can't even say at this stage what songs for sure are making it and what songs aren't," Dr. Luke told RollingStone.com. "We're working with a lot of producers and overseeing it with her A&R and record label and management and trying to make something cohesive." Bottom line, he said, is that "it's not done."

Not to worry: Spears apparently is so speedy when it comes to hitting the studio, Luke has no qualms that they'll make the March 15 deadline. "Britney's really fast," Dr. Luke said. "She gets it done."

The super-producer also opened up about the album's debut single, "Hold It Against Me," noting that it was meant for another pop princess: "We might have played it for her, but it definitely wasn't a Katy Perry record," he explained. "We had it for a while. I wanted to make sure it didn't sound like everything else I've done. I brought it into [producer] Billboard, and he just killed it. It can be hard in the verse, and the bridge is super, super hard, but the chorus is super pop. You can play that chorus acoustically on a guitar and it's still going to sound great."

Others producers on the album include Bloodshy and Benny Blanco. Dr. Luke took to Twitter to tease fans with possible track titles for the release. He shared, "One of these titles could be a new brit song: a) booga dooga b) the sun is up c) seal it with a kiss d) monkey c monkey do."

Other reported titles are leaking as well. According to a posting on Popjustice.com, other Femme Fatale tracks might include "Antidote" (described as a Ke$ha-esque dance track), "Switch You On" (a mid-tempo song about sex) and "I I I Wanna Go O O" (another dance track).

Are you excited for Britney's new album? Tell us in the comments!