"LMAO Star Magazine!" the singer tweeted of the tabloid's latest claim. "I don't know if you [doctor] the pics or pic the worst one you can find, but I'm far from pregnant . . . "
In fact, although the once pin-thin Rimes has been showing off a healthier, curvier figure lately, she says she's recently lost weight. She added in her tweet that she "just dropped a jean size."
Rimes is already a stepmom to Mason, 10, and Jake, 6, her husband's two sons with ex-wife Brandi Glanville. In May, the "Spitfire" singer told Us Weekly that she's not in a rush to start a family of her own yet.
"We talk about having kids all the time and I would love to, but it's gonna be a second," she said. "I'm still young and fertile -- it's all good!"
"I was just with the kids for the last two days taking care of them on my own, and trust me . . . I have a newfound respect for working moms who do it all by themselves," Rimes added about caring for the boys. "It was my birth control for a little bit -- so overwhelming!"
Want more of Us? Get our biggest scoops delivered directly to your inbox! Click here to sign up today for the Us Weekly email newsletter.
This article originally appeared on Usmagazine.com: LeAnn Rimes: "I'm Far From Pregnant and Just Dropped a Jean Size"