The model and her fiance Wiz Khalifa are thought to be expecting their first child in January 2013 and Amber wants to move up their wedding date to October to avoid getting married when she is heavily pregnant, according to MediaTakeOut.com.
Rapper Wiz proposed to Kanye West`s former girlfriend earlier this year and although the pregnancy was a surprise, the pair are said to be thrilled about the baby and are already making a number of lifestyle changes to prepare.
A source told RadarOnline: "Amber and Wiz unexpectedly got pregnant, but they`re really happy to be starting a family together.
"Amber`s already had to make some big lifestyle changes, like not smoking cigarettes anymore. As a model she`s used to having a thin waist, so this is going to be an adjustment for her."
Speaking about the proposal previously, Wiz revealed he showed Amber the "real" him when he popped the question.
He said: "[It was] real simple. It was in the morning time. I just rolled out of bed and got the ring out of the laundry room. Didn`t brush my teeth. I was sober, I gave her the real me.
"I didn`t cry. But she was crying so much she didn`t know what to do. I was like, `Say something, yo! I didn`t let her take time to think about. Knew she was going to say yes."