The 31-year-old star is expecting her second baby and the father of her unborn child is Muse rocker Matt Bellamy. Hudson already has a seven-year-old son Ryder from her marriage to Chris Robinson.
Speaking about her pregnancy on The Graham Norton Show, she said: 'I'm just starting to pop. We have a couple of names but we're not telling anyone. People tell you so much [about being pregnant] it drives me nuts.
'It feels like a girl, but I don't know. Ryder [my son] thinks it's a girl.'
However she dismissed speculation they are planning to marry.
She said: 'No, no, not that I know of! I don't like putting that sort of pressure on it and I don't feel it necessary to get married.
'I am 31, I already have one child and have had one divorce so it is not necessarily the golden ticket. I just want to be happy.'