The Girls Aloud singer agreed to marry NFL footballer Jason Bell after he proposed to her by surprise in Los Angeles last week, but he had to get down on two knees instead of one because of a football injury.
Asked if she was wearing an engagement ring by presenter Scott Mills during an appearance on British station Radio 1, she said: "Yes that is an engagement ring. It happened last week.
"I just got back from London and he was in New York and he surprised me with a ring and stuff, while I was in my pyjamas! If I had known I would have had a blow-dry or at least had a manicure or something!
"It happened in Los Angeles. He was really nice about it. He got down on two knees, not one knee because he had played football for a while so he was all banged up. It was different! It was really, really nice. He's probably dying now."
Before she started a relationship with Jason, the 25-year-old pop star dated several famous men, including 'Desperate Housewives' hunk Jesse Metcalfe and Northern Irish soccer player Neil McCafferty.