Britney Spears is back in rehab, and hoping third time is the charm.

The emergency custody hearing that Kevin Federline wanted has been cancelled because of the new development. There will be no custody hearing today.

K-Fed is reportedly concerned for Brit’s welfare and wants her to get the help she is now seeking-he’s giving her one last chance.

IF she leaves rehab before getting full treatment, Kev will immediately go to court seeking orders allowing him unquestioned full custody of the children.

Brit supposedly showed up at her estranged husband’s house last night but he wouldn’t’ let her in.