The American actress told chat show host Ellen DeGeneres that she was cool, calm and collected when she went into labour at one in the morning.
"It was very easy. I went into labour at about one in the morning and I very calmly had my bags packed and woke my husband up after about three hours of walking up and down my hallway," said Hilary.
"Then I'm like, 'Okay, it's time to go, let's go now.' We got in the car and drove to the hospital and that was it."
Hilary also revealed Luca's birth was a real family affair, saying: "Things start rolling. All of the sudden the doors bust open and my sister and my mom come flying in and they're like, 'We got barbeque chips and root beer guys.' I'm like, what? I'm pushing!"
Hilary went on to gush about motherhood on the show, saying she loves seeing Luca change and grow so much in such a short space of time.
The little boy is Hilary's first baby with husband, Mike Cromie.
Watch the video below to see Hils' interview in full.