Published Tuesday, 28 August 2012
The singer, 34, announced the baby news via Twitter on Tuesday, revealing she's struggling with morning sickness.
Frost wrote: "So tired, so pukey, so pregnant... so happy!" and later added: "Oh & it's twins!!!!! #arrrrrrrrrrrrgh."
The pop star already has a four-year-old son, Caspar, from a previous romance but the twins will be her first and second children with Spanish husband Vicente Juan Spiteri, who she wed last year.