Justin Bieber performs in London, England. Credit: Matt Kent/WireImage.com

The show must go on. Justin Bieber had a bit of a scare when he fainted mid-concert on Thursday, March 7, but he didn't let that stop him from finishing the performance.

"Justin fainted onstage tonight during his concert in London when he fell short of breath," the 19-year-old "Boyfriend" singer's rep tells Us Weekly. "He left the stage for 20 minutes, then came back and finished the show. He is now on his way to a doctor to get checked out and see what is wrong."

It is not yet known what caused the episode, but there's no doubt it's been a stressful week for the pop superstar. On Wednesday, March 6, Bieber took to Twitter to talk about rising above the drama and focusing on his loyal fans, a.k.a. Beliebers.

"I'm focused on the good things in life. I'm blessed and not forgetting it," he wrote. Later, he added: "I will continue being me. I will continue to serve, to perform, to care, to love, to smile, to dance, to play, to sing...and you are welcome to join, because I carry no hate. We got too much love for that. I'm about the music."