Beyonce has penned a letter to her fans apologising for cancelling a gig.
The star, 31, who has sparked rumours that she could be pregnant, called off the Tuesday night gig in Belgium because of dehydration and exhaustion.
The singer's publicist said Beyonce has been advised by her doctors to rest and that the concert would be rescheduled.
But the mum-of-one has posted a handwritten message on her Facebook page saying that she is now feeling better and that she'll be performing again on Wednesday night.
"To my dearest fans in Antwerp. I've never postponed a show in my life," she wrote.
"It was very hard for me. I promise I will make it up very soon. I'm sorry if I disappointed you," she added.
"Thank you for your concern. I'm feeling much better now. And I'm ready to give you a great show."
"See you tonight. All my love, Beyonce."
Beyonce, whose appearance at a Met Gala event sparked speculation that she could be expecting her second child, launched her Mrs Carter World Tour last month in Belgrade, Serbia.
The tour wraps on August 5 at the Barclays Centre in Brooklyn.