The 30-year-old singer, having been wed twice before, is planning to say 'I do' in a private ceremony with Trawick, reported People magazine.
"There's no truth to any second thoughts about their wedding. They're fine and both look forward to working again when The X Factor gets started. They've had a great summer," said a source.
Speculation about trouble between Spears and Trawick surfaced recently when she was photographed outside court without her engagement ring.
But, according to the source, "she was not wearing her ring last week at court because she took it off during an Elizabeth Arden [photo] shoot and Jason was holding it for her. He simply forgot to give it back until later."
The insider said the wedding but won't happen until after Spears finishes her busy commitments for The X Factor.
"Even though Britney has been married before, she looks at her wedding to Jason as her real wedding. It'll be small and intimate with family and friends, and will be about she and Jason. They're already such a loving family," the source said.