Hilary Duff: 'Luca Is Getting So Big'

Hilary Duff smiles for the cameras while out and about on Tuesday (May 22) in Hollywood.

Later that day, the 24-year-old actress visited the Art Institute of California.

PHOTOS: Check out the latest pics of Hilary Duff

“Hi tweeties!! Sorry I went missing!!!” Hilary tweeted after not being online for a week. “Been super busy in mom world! Not an easy job but the most rewarding! Luca is getting so big! It’s crazy!”

She later added, “Luca and I are off to the doctor to get his first shot! Poor guy! :(”

15+ pictures inside of Hilary Duff out and about…