Singer Beyonce Knowles is reportedly trying for another baby with husband and music producer Jay-Z.Knowles is finished with her worldwide tour and the couple, already parents to daughter Blue Ivy, is now keen to have a second, reports showbizspy.com."They've been trying since February. Her friends are convinced she's already pregnant. The same things that happened during her pregnancy with Blue Ivy are happening again. said a source," said a source.The singer has been letting her hair go natural again, has changed her diet and the source added :"she's always blushing and giggling."