The 24-year-old star is expecting her first child with hockey player husband Mike Comrie.
She recently went on The Ellen DeGeneres Show where she was asked if she knows the sex of her unborn baby.
She said to Ellen: 'I do, but I haven't told anyone yet. I wanted to tell you first.'
Ellen tried to guess what the sex of the baby is by asking her a number of questions. She said: 'Are you craving anything?... I don't have a clue. I'm just going to guess boy.'
Hilary then said: 'It's a boy! Good job. I had a feeling it was a boy the whole time.'