Kelly Clarkson at her wedding in Tennessee. (Credit: Archetype Studio Inc.)

After admitting for the past few months that she wanted to have a baby immediately, Grammy winner Kelly Clarkson is officially pregnant.

"I'm pregnant!!! Brandon and I are so excited! Best early Christmas present ever :)," the "American Idol" winner tweeted earlier Tuesday.

Clarkson, 31, married Brandon Blackstock last month in Tennessee in a small ceremony with Blackstock's two children from a previous relationship - Savannah, 12, and Seth, 6 - present.

Read: New Details on Kelly Clarkson's Tennessee Elopement

Before the wedding in October, Clarkson told ABC News just how ready she was to expand her new family with a baby of her own.

"Like soon! Brandon, he's a great dad and we wanted to make sure it's cool with [his kids], but they are really pumped about it," she said. "We actually, probably, want two more, and he's got two, so four total. [The oldest] will be in her teens, so that's kind of like a live-in baby sitter."

Related: Kelly Clarkson Marries Brandon Blackstock

Clarkson has said how much she loves being a stepmom to Blackstock's two children.

"I actually really dig the mom thing. … I am quick to go, 'I told you not to touch that!'" she told Ryan Seacrest in August. "I am totally my mom. My mom was a hard mom."

Congrats to Kelly and Brandon!