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The couple had been planning to make the announcement to mark Mother's Day, but had been ‘blindsided’ when the news had leaked on a celebrity website.

The source goes on to add that Chyna suspects Rob’s family had leaked the news in a bid to promote their reality TV show, "Keeping Up With The Kardashians," as Rob is set to appear in upcoming episode.

"She had that moment stolen from her."

Blac had obviously kept her inner circle in the loop of things before they had shared the news with a cartoon photo of the model sporting a huge bump via their Instagram pages on May 6, 2016.

ALSO READ: Blac Chyna's ex congratulates her on pregnancy news

Watch video clip below: