In a Friday posting on her MySpace page, the singer, 40, writes that she and husband Michael Lockwood, 45, are "beyond thrilled and blessed, elated and saturated in happiness" over the twins they will welcome this fall.
The pair will be the first children together for Presley and Lockwood, a musician. The expectant mom, who proudly displays her baby bump in the September issue of Marie Claire, has daughter Riley, 19, a model, and Benjamin, 15, with ex-husband Danny Keough.
In her first blog entry since May, she expresses her gratitude to fans for well wishes to the couple, who wed in January 2006. "Thank you so much for all of the amazing positive energy and beautiful well wishes," she writes, adding, "We love reading them."
To those anticipating her third CD, she explains that belting it out is not so easy in her current state.
"For those who have been asking me," writes Presley, who released her debut album, To Whom It May Concern, in 2003 and the follow-up, Now What, two years later. "I am not recording at the moment as there isn't much room for breathing and singing right now, most of that area has been taken up and I can't really sing a line without running out of air halfway though."
Recording Will ResumeAssuaging antsy listeners, she adds, "Writing and recording will resume when the little occupants in there have decided to join the outside world."
The otherwise euphoric rocker also used a portion of her post to vent about life under constant media scrutiny.
"In the past couple of years, high profile type people seem to have less and less rights," observes the only child of Elvis Presley. "Less privacy and protection. The onslaught of Internet and tabloid sites mostly want only blood now. They have managed to make being a public figure a 24/7 public stoning and execution of various sorts. Some obviously more brutal than others."