Valentine's Day is usually a day for celebrating love with a significant other -- but not for Miley Cyrus, who said that was the day she knew she and former fiancé Liam Hemsworth were done.

Cyrus spoke with Fashion Magazine for its November issue, which hits newsstands Oct. 7, and said her new song "Drive" was written about Hemsworth in February, months before their split in September, according to ABC News.

"I wrote ("Drive") while I was working on Valentine's Day. Emotionally it was such a hard time," she told the magazine. "It is about needing to leave someone but not really wanting to completely cut yourself off from the relationship," she added. "It's a time when you want to leave but you can't. It's also about moving on."

And move on she eventually did.

After a shocking Video Music Awards performance by Cyrus -- the twerk heard 'round the world -- and months of speculation that the couple were indeed over, the couple announced Sept. 16 that they had split, reports ABC News.

After fighting back persistent rumors of a breakup, Cyrus and Hemsworth recently officially ended their engagement, a rep for actor Hemsworth confirmed.

Cyrus, 20, and Hemsworth, 23, announced they were headed for marriage in June 2012. Since then, however, the couple's relationship has been plagued with rumors of infidelity and temporary splits, according to CNN.

Cyrus spoke more than once about the speculation this spring, tweeting in early March that she was "sick of (Los Angeles) and sick of the lies that come with it," assuring her fans that she hadn't called off her wedding. The "Wrecking Ball" singer met Hemsworth on the set of 2010's "The Last Song," and although they had a bumpy relationship pre-engagement, both sounded content.

"She makes me really happy," Hemsworth shared with Details magazine in February 2012. Months later, Cyrus was "looking forward to a life of happiness" with the "Hunger Games" star.

But according to People magazine, which first reported the scrapped engagement plans, lately Cyrus has had "more breakups than bonding moments" with Hemsworth, according to CNN.

While Cyrus had remained tight-lipped about their romance, the writing seemed to be on her Twitter wall. A few hawk-eyed observers caught on this weekend that Cyrus has stopped following Hemsworth on the social media site.

It's unclear what the status of their relationship is now that they're no longer engaged, and reps have declined to comment further. What is clear is that both stars have a busy fall ahead, according to CNN.

Cyrus burst into the big time in 2006 on Hannah Montana, a TV show about a girl who lives a double life as an average teenage school girl named Miley Stewart by day and a famous pop singer named Hannah Montana by night, as we previously reported.

Cyrus wore a purity ring several years ago and, in 2008, she said that she wanted to be pure until marriage, according to examiner.com.

 (In 2012, her view on virginity changed saying "it's a beautiful and magical thing.")