(Photo credit: Christopher Polk/Getty Images)

Kelly Clarkson has babies on the brain these days. She'll tie the knot with fiancé Brandon Blackstock after her tour with Maroon 5 ends next month, and soon afterwards, she says, "I'm going to want to have a baby."

In fact, Clarkson, 31, has already started making changes to her diet and lifestyle to get herself ready for pregnancy. She explains, "It's all about just making my body the most healthy inside out. And I'm reading all these books. I have a huge thyroid issue of mine that I'm dealing with."

See Kelly Clarkson's First Engagement Photo

Clarkson is also stepping into her role as a stepmom to Blackstock's two children, who are 12 and 6-years-old, respectively. They all get along very well, and Clarkson is thankful to have such great kids in her life.

"Granted, none of them are teenagers yet, so come back to me [later]," Kelly says. "They're so great, and it just makes me so excited."

Kelly Clarkson Shares a Second Engagement Photo

Blackstock's daughters are also ready to expand the family soon, too.

Says Clarkson, "Savannah, the 12-year-old, is, like, 'I want a little sister.' She's so excited."

As previously reported, the couple is planning to elope as soon as next month.