Meghan Trainor burst onto the music scene in 2014 with her hugely successful track 'All About That Bass,' and although the song promotes a positive body image, the 21-year-old singer wasn't always confident in her own ability.

Meghan Trianor
Trainor recently opened up about her own insecurities

Trainor recently opened up about her lack of self-esteem in the March issue of Seventeen magazine, in which the Massachusetts native admitted that she "never thought I'd be a pop star" because she didn't "look like Rihanna."

"When I saw photos of myself, I would think, I look awful," she recalled. "There's a double chin!"

More: Meghan Trainor Explains Why She Will Never Wear Provocative Outfits While Performing

However, Trianor's mentality towards her goals changed when she met a female fan while signing autographs, just after the music video for 'All About That Bass' was released.

"This girl came up to me bawling and said, 'You make me feel pretty again. Thank you,'" she explained. "It really resonated with me that this girl was so gorgeous, and she didn't even know it. It's a mental thing. Just recently I was thinking, 'I'm confident now, and I look good,' and that's because I've started saying those words out loud more. So now when I see pictures, I'm like, 'Oh my God, why would I hate myself at all? I look incredible in that picture!'"

Along with her positive attitude, Trainor has also come to terms with not having love in her life at the moment, especially since her career is taking off.

More: Meghan Trainor Admits She Hasn't "Made Any Money" Despite 'All About The Bass' Success

"I knew my life would be complicated if my dreams of becoming a success in music came true. And I knew I'd have to work hard to achieve those dreams, and that they'd have to take a front seat in my life," she told the mag. "So even though I went cray in high school, now I haven't kissed a boy in forever. I keep telling myself that the right guy is going to be worth the wait. When I find the one, it's going to be like, 'Damn, that's why you took so long! 'Cause you're awesome!'"

The latest issue of Seventeen hits newsstands Feb. 17.