Hilary Duff: I Can't Believe I Have a Baby!

By Dahvi Shira

03/23/2012 at 04:25 PM EDT

Hilary Duff is smitten.

The new mom, 24, who gave birth to son Luca Cruz Comrie on Tuesday, is sharing her joy with the world, calling her little one, "the most wonderful, sweet, adorable baby."

"Wow, I can't believe I have a baby!" she Tweeted on Friday. "Thank you for all the messages and well wishes. I love you all so much."

PHOTOS: Hilary Duff's Cool and Casual Bump Style

Duff announced in August that she was expecting her first child, saying that she and hubby Mike Comrie were, "ready to start this new chapter in our lives."

She described the experience of being pregnant as, "Kind of like a little alien has taken over your body. You just don’t quite feel normal."