Beyonce is opening up about a heartbreaking event no woman wants to go through, and says that music turned out to be the best form of therapy for her.

Before she became pregnant with Blue Ivy, she said, she was pregnant with another child who lost the heartbeat early in the first trimester. The star said that hearing the sound of her baby’s heart had been the most “beautiful music” she’d ever heard, and to lose that was devastating.

“I picked out names,” she said. “I envisioned what my child would look like . . . I was feeling very maternal. I flew back to New York to get my check up — and no heartbeat. Literally the week before I went to the doctor, everything was fine, but there was no heartbeat.”

Using music as a way to overcome that emotional time, Beyonce wrote a song about her loss; it would be the first one she’d write for her album.

“I went into the studio and wrote the saddest song I’ve ever written in my life. And it was the best form of therapy for me, because it was the saddest thing I’ve ever been through,” she said.

Beyonce and hubby, Jay-Z, have been extremely doting parents and were fairly secretive about her pregnancy with Blue Ivy, and now we know why. They’re still highly protective of her, rarely allowing her to be photographed by the media. But, she says, keeping the baby a secret was difficult.

“Being pregnant was very much like falling in love,” she said. “You are so open. You are so overjoyed. There’s no words that can express having a baby growing inside of you, so of course you want to scream it out and tell everyone.”

The superstar is set to perform the halftime show at the Super Bowl this weekend, after much speculation regarding her performance of “The Star Spangled Banner” at President Obama’s inauguration earlier this month.