Until now the pair had refuted rumours Carey was pregnant with twins but Cannon confirmed the news this morning on his radio show.
The rapper claims Carey was asked about the rumours by Michelle Obama following her performance at TNT's Christmas in Washington.
"At this point she hadn't told anybody anything because the doctors advised us to keep it to ourselves until we get further along," Cannon explained, according to People. "And because of the excitement, because of the emotion, she was overwhelmed and she shared with the President and First Lady that we are having twins."
Earlier this week, Cannon insisted that he had no preference of the babies sex as long as they were 'happy and healthy'.
The couple announced their pregnancy in October this year although Carey's due date is still unknown.