Beyonce is now the proud mother to baby Blue Ivy, almost 13 months, but she opens up in her new HBO documentary Life is But a Dream, which premieres on Feb. 16, that she had been pregnant before - and it ended in tragedy.
'About two years ago, I was pregnant for the first time,' Beyonce reveals in one scene of her documentary. 'And I heard the heartbeat, which was the most beautiful music I ever heard in my life.'

Beyonce and Jay-Z, who wed in April 2008, were so excited to be parents.

'I picked out names,' Beyonce adds. 'I envisioned what my child would look like . . . I was feeling very maternal.'

How Beyonce Found Out She Lost Her Baby
But when she went back for another checkup, she received horrible news.

'I flew back to New York to get my checkup and no heartbeat,' she says in the documentary. 'Literally the week before I went to the doctor, everything was fine, but there was no heartbeat.'

Beyonce: Writing New Music Was Therapy For My Miscarriage
'I went into the studio and wrote the saddest song I've ever written in my life,' she says in the movie. 'And it was actually the first song I wrote for my album. And it was the best form of therapy for me, because it was the saddest thing I've ever been through.'

Beyonce doesn't reveal which song was inspired by her miscarri.