A high-profile engagement, endless speculation about major uterine developments and plenty of face time on TV and magazines couldn't put Ashlee Simpson over the top. As it were, Jessica's baby sister managed just a bittersweet No. 4 debut for Bittersweet World, failing to extend her run of chart-topping albums and looking up at Mariah Carey, Leona Lewis and even the New Zealand novelty act Flight of the Conchords.

Simpson, who sources tell E! News is preggers with new Fall Out Boy fianc� Pete Wentz's spawn (the couple has been coy about whether there is a bun in the oven), had both her previous albums debut at No. 1. - more this week's charts

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