The Black Eyed Peas singer - who is married to `Transformers` star Josh Duhamel - admitted she is currently focusing on her career and thinks she would struggle to try and work while pregnant.
She explained: "Everyone tries to rush you into everything in the press these days, but for me right now it`s all about Black Eyed Peas - there`s no room in my schedule to have a child.
"Even if I wanted to get pregnant, there`s no way I could perform on stage and be pregnant, I would feel too guilty."
The `My Humps` hitmaker admitted that when she and Josh, 37, eventually do start a family, her music career will take a back seat.
She added to Britain`s OK! magazine: "Once I have children, the kids come first.
"One thing at a time for me. There`s a saying, I forget who said it, but it was a really good quote that said women can have it all, just not all at once. It-s too much if you-re doing everything all at once."
Josh - who married Fergie, 35, in January 2009 - has previously spoken of his desire to have children.
He said: "We`re thinking about kids. I don`t know when. She said that she`d be pregnant twice. So I said, `Great, we`ll have two sets of twins!` "