'Hills' Star Heidi Montag Says She'll 'Be Married Forever'

Reality star/ singer tells 'Extra' that she's legally taken Spencer Pratt's last name.

Come this weekend, Heidi Montag and Spencer Pratt will have been married for two weeks. And the couple assure all their harshest critics — which at times has even included members of Heidi's family — that they vow to make this marriage last forever.

"It's real love," Heidi told "Extra" in an interview airing Thursday (May 7). "And we will be married forever and ever and ever!"

Heidi has taken a huge step toward showing everyone that this is the real deal. "I legally changed my name to Pratt. ... I'm very excited," she gushed. Spencer, who calls married life "amazing," added, "We're going to the DMV and we're getting the license, and I'm framing it."

Heidi, who wore a Monique Lhullier gown to the wedding in Pasadena, California, on April 24, said that moments before they married, she knew she had made the right decision. "I was just sitting there in my dress, like, 'I am really about to marry the most amazing man, and this is such a great experience.' "

She said the dress was the one she had always wanted. "I thought about my dress for years. I knew everything I wanted," she said. "I knew I wanted a strapless, gorgeous, big, flowy, princess, fun, amazing dress, and that's what I had. I wanted it to be really classic but young and fun and fresh. I felt like a princess, and it was perfect."

Although the pair have yet to have a honeymoon, they recently took a trip down to Mexico to shoot the music video for Heidi's song "Blackout." They took every precaution to make sure they didn't catch the swine flu. "We were masked up. I was scared," Heidi said, with Spencer adding, "I didn't even want to take my mask off. ... I have enough to worry about in Hollywood [without] the swine flu."