The Fall Out Boy rocker, who finalised his divorce from Ashlee Simpson earlier this month, was rumoured to be expecting his second child with Camper next year.
However, Wentz's rep told US Weekly that such reports are "absolutely not true" and that Camper is definitely not pregnant.
Wentz and Simpson are parents to 3-year-old son Bronx Mowgli.
Wentz has previously admitted that he loves being a father and hopes to expand his family and have more children in the future.
He and Simpson announced their split in February after less than three years of marriage, but said that they remain committed to getting along for the sake of their child.