Extra TV is reporting that Britney Spears checked into rehab after leaving Miami on Wednesay. However, it appears the popstar may have already checked out. TMZ has learned that the rehab facility was somewhere outside the U.S. and that Spears refused to stay. Her rep has not been reached for comment.Update: A source has confirmed to People that Britney did indeed check into Eric Clapton's Crossroad's Center in Antigua "two or three days ago," but left after just one day. Spears's visit took place before her trip to Miami, rather than afterward, as widely reported.