The couple has been dating for nearly five years.

Credit: Getty Images

Britney Spears is officially a bride-to-be.

Over the weekend, the 39-year-old pop star announced her engagement to boyfriend Sam Asghari, sharing the exciting news Sunday with her 34 million Instagram followers. "I can't f—king believe it," shared Spears on Instagram, who also showed off her dazzling diamond ring in Sunday's post. (Related: Sam Asghari Says Girlfriend Britney Spears Is His Fitness Inspiration)

Asghari, 27, popped the question at Spears' house and presented her with a stunning 4-carat round-cut stone, Page Six reported Sunday. "You like it?" asked Asghari in Sunday's Instagram video, to which Spears exclaimed, "Yes!" Asghari also had Spears' nickname, "Lioness," engraved inside of the pop star's band, according to Page Six.

Asghari, who is an actor and fitness expert, has been dating Spears for nearly five years. Following Sunday's announcement, the future newlyweds received a flood of well-wishes from fans on Instagram. (Related: Celebrities Are Speaking Out In Support of Britney Spears)

"Congratulations love!! So happy for you! Welcome to the club!" commented fellow bride-to-be Paris Hilton on Spears' post. Trainer Sydney Miller also gushed, "He's SO LUCKY!!!!"

Although it's unclear when the couple will tie the knot, Spears has yearned to start a family with Asghari for some time. During a June testimony about her conservatorship, Spears said that she wanted to marry Asghari and have a baby, but was unable to due to the current circumstances.

"I was told right now in the conservatorship, I'm not able to get married or have a baby, I have an (IUD) inside of myself right now so I don't get pregnant," said Spears in June, according to People. "I wanted to take the (IUD) out so I could start trying to have another baby. But this so-called team won't let me go to the doctor to take it out because they don't want me to have children — any more children." (Related: What You Know About IUDs May Be All Wrong)

Spears, who shares sons Sean Preston, 15, and Jayden James, 14, with ex-husband Kevin Federline, has been under conservatorship since 2008. Essentially, this legal arrangement occurs when a person or persons is given control to manage the affairs of someone who is unable to make their own decisions, as considered by the court. Jodi Montgomery is Spears' current conservator, who oversees her personal matters (such as her caretakers and whom she can visit). The pop star's father, Jamie Spears, is in charge of her financial affairs. (Related: Britney Spears Spoke Out for the First Time Since Her Conservatorship Hearing)

Recently, Spears' father filed a petition to end the 13-year conservatorship. Judge Brenda Penny, who currently presides over the case, would have to approve the move, however.

Given the recent news, Spears and her fans are certainly celebrating. Congrats to the couple!