The 24-year-old singer-and-actress is pregnant with her first child with husband Mike Comrie and she has now discovered the gender of her unborn baby.
She told TV talk show host Ellen DeGeneres: "I haven`t told anyone yet. I wanted to tell you first. I just found out.
"It`s a boy! I had a feeling it was a boy the whole time."
Hilary - who is "a little over four months" into her pregnancy - admitted she and Mike cried when they learned she was expecting, despite the fact the 31-year-old NHL ice hockey player was initially sceptical that she was carrying a baby.
She said: "My husband makes this joke that I think I`m pregnant like 12 times a year.
"So when it actually happened he was in the shower. I just ran in and he was in the shower and I just held up the test and I was like, `Oh my god.` And he was like, `AHH!` He was soaking wet. We were just like a mess and started crying. It was really exciting!"
The former `Lizzie McGuire` star is thrilled with how well her pregnancy has gone so far.
She said: "I feel great, actually. It`s been super-easy."