Writing under the video, Jessica appeared over the moon to be announcing her exciting news.
Since becoming a mother, Alba has shifted her attention away from Hollywood and toward her business endeavor, The Honest Company, which specializes in non-toxic household products.
The family is now vacationing in Hawaii - Jessica was spotted in a bikini over the weekend, but there was no sign she was expecting.
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She was roped in to play the lead role in " Quantico " an American TV show which is now all set for a third season. Priyanka's second Hollywood project, A Kid Like Jake starring Jim Parsons, is slated for a 2018 release.
She, together with her husband Cash Warren, was happy about the coming of their third bundle of joy.
The 36 year old completed her pregnancy look with a pair of chunky black wedges, which added a summery edge to her dark ensemble. Just recently, Alba took to Instagram as they celebrated the ninth birthday of their child, Honor.