The soon-to-be mom of two fought back tears during a moving performance of "Piece by Piece" on "American Idol."

Credit: American Idol/YouTube

I wasn't prepared to break down watching Kelly Clarkson sing her song "Piece by Piece" on "American Idol" the other night, so I'm gonna warn you guys right up front: You. Will. Cry.

The expectant mama wrote the song when she was pregnant with her first child, River Rose, and she explained to Glamour last year that it's based on her relationship (or lack thereof) with her father. "I don't know what my father went through as a child, and I don't know why he left and made the decisions he made, but everyone's human," she said. "I don't understand it for me, but I understand the depth of what that is—having a child—now, and he's made me want to be that much more present in my family."

Not surprisingly, the ballad is hauntingly sad. "I begged you to want me but you didn't want to," she sang, choking back tears as her eyes welled up. She then stopped twice while trying to make it through bittersweet lyrics that highlight the good she sees in her current lover (husband Brandon Blackstock), who, "piece by piece," puts her back together and teaches her that men can "stay" and "be kind."!

"Idol"—now in its final season—famously launched Clarkson to stardom during its debut back in 2002, just a few months after my own daughter (now almost 14) was born, so I admit my emotions were already running high as I watch her breakdown. But I was far from the only one who needed to pause the screen so I could go get some tissues.

"You have us all in tears," said Ryan Seacrest after the performance, speaking for himself, the live audience, and judges Harry Connick Jr., Keith Urban, and Jennifer Lopez. "The emotion that you exude always, but especially in that important's just incredible."

We couldn't agree more. Although Clarkson joked that something else might be at play. "I'm pregnant and it's nostalgic, and I can't believe it's the last season," she said. "I'm really sorry I just bawled."

No need to apolgize, Kelly—following the hearfelt performance, "Piece by Piece" nabbed the No. 1 spot on iTunes!

Hollee Actman Becker is a freelance writer, blogger, and a mom. Check out her website for more, and follow her on Twitter at @holleewoodworld.