The singer, who is believed to be four months gone, and her husband Nick Cannon have apparently only shared the news with close friends and family.
An insider told RadarOnline: "Nick has been telling friends how excited he is to be a dad."
According to reports, Carey is delighted to be having a baby after trying to conceive for a long time.
Another source said: "Mariah has tried so hard to get pregnant. She's very excited. She wants to wait as close to full-term as possible before going public with the news to her fans."
