Fergie has announced that she's got a little Pea in the pod -- and will give birth to her first baby this fall.

She and hubby Josh Duhamel sent out matching tweets, with hers saying, "Josh and me and baby makes three." She added a Photoshopped picture showing her and Josh posing together as children. The singer promises to deliver updates on her pregnancy under the hashtag MyLovelyBabyBump.