Mystery surrounds Britney Spears' no-show at a planned press conference in Los Angeles yesterday (04MAY06). The pop superstar invited selected media representatives, journalists and record industry executives to the Los Angeles Convention Center - but failed to show up. The 24-year-old did not reveal why she was calling the press conference, but it was widely anticipated she would officially announce her second pregnancy with husband KEVIN FEDERLINE. But the event didn't take place and there's no word from the Spears camp about why the plan was scrapped or whether it will be rescheduled.