The 28-year-old posted a surprise picture of herself with the caption: "I am having a baby. X". But she's yet to announce who the father is.
It's rumoured the baby daddy is her on/off boyf and former fiancee Jason Bell. The pair dated for three years before announcing their one-year engagement had ended in June 2011.
At the time, Nadine confirmed the split on Twitter, writing: "A few weeks ago Jason and I broke up. We are great friends and decided we are better this way. I'm in NYC working & I love all your support.x".
BUT in Match this year the couple sparked speculation they were back ON when Jason flew in to the UK to watch Nadine on stage at the O2.