The Australian singer announced that he is to become a father for the third time last month, with his girlfriend of a year, Emily.
But he insists that rumours suggesting he has been engagement ring shopping and is preparing to propose are "completely untrue".
Writing in his column for new! magazine, he said: "A couple of magazines published stories last week saying I am planning to propose to Emily and have already been ring shopping.
"One even claimed I am considering spending £60,000 on a ring. All I will say is that the stories are completely untrue and made up. People are just writing what they want.
"I have never discussed anything like that with anyone, so only believe what you read in my column."
The Mysterious Girl singer and the 23-year-old medical student, who is thought to be around four months pregnant, met through Emily's father, a doctor who performed surgery on Peter in 2010.
Speculation that Emily was pregnant started when Peter was seen placing his hand on her stomach at an event in June.
He is said to be "absolutely thrilled" about the news.
"We were going to keep this to ourselves a little bit longer, but as everyone's been asking, I am very happy to tell you that Emily and I are having a baby, and we are over the moon," Peter shared in his column.
"Emily will make a brilliant mum," he added.
The baby will be Peter's third child – he already has son Junior, eight, and five-year-old daughter Princess with ex-wife Katie Price – and his first with Emily.