Hunter told ABC's "Good Morning America" on Tuesday that she and Edwards were still a couple until late last week, as details from Hunter's memoir became public.
The break-up was painful, but Hunter said Edwards will still be involved with their daughter, Quinn, who is 4 years old and lives with Hunter.
"We are a family, but as of the end of last week, John Edwards and I are no longer a couple," Hunter said on Tuesday's show. "We decided together to end it."
The book, "What Really Happened: John Edwards, Our Daughter and Me," is being released Tuesday through a Dallas-based boutique publisher, BenBella Books. The Associated Press reported on the book last week.
In the book, Hunter describes intimate details about her affair with Edwards, whose campaign hired her as a videographer, and sheds light on his thoughts as federal prosecutors mounted a case against him on illegal campaign contribution charges.
Prosecutors had accused the Democratic politician of masterminding a scheme to use about $1 million in secret payments from two wealthy political donors to hide his pregnant mistress as he sought the White House in 2008.
According to Hunter, Edwards told her he would probably end up in a low-security prison in Virginia if he was convicted, and Hunter said she planned to move nearby with their daughter if that happened.
A judge declared a mistrial last month, and federal prosecutors have opted not to retry Edwards.
Hunter's memoir also includes intimate details about her affair with Edwards as his wife, Elizabeth, was dying of cancer. On Tuesday, Hunter said she felt it was necessary to tell the truth about her relationship, even if doing so was painful for her, Edwards or his other children.
Saying that she still loves Edwards, and that she believes he still loves her, Hunter said on Tuesday that she was unsure of the future.
"We'll see what happens," she said. "I have no plans."