The couple announced their engagement in December but recent rumours have suggested that the new X Factor USA judge is having second thoughts about the wedding.
However, a source has now told People that there is "no truth" to the speculation.
"They're fine and both look forward to working again when The X Factor gets started," the insider said. "They've had a great summer."
The source also explained that when Spears was photographed without her engagement ring recently, it was because she had taken it off for her Elizabeth Arden photo shoot.
"Jason was holding it for her," the insider said. "He simply forgot to give it back until later."
However, the source revealed that Spears and Trawick are unlikely to wed until after The X Factor, saying: "Even though Britney has been married before, she looks at her wedding to Jason as her real wedding."
The X Factor USA will return for its new season on September 12 on Fox.
Watch a promo for the new season of The X Factor USA below: