Hilary Duff's on son's teething: 'It hurts'

A very pregnant Hilary Duff heading into a Medical Office Building Beverly Hills Los Angeles

Hilary Duff has revealed that her son is teething.

The former Lizzie McGuire star welcomed her first son with husband Mike Comrie in March.

In a Twitter post, Duff discussed her son's progress, writing that the four-and-a-half month old baby is sporting his first tooth.

"Luca is cutting a tooth!!! It's the cutest/saddest (because it hurts) getting so big my boy!! Gunna have a little toof lol (sic)," Duff tweeted.

In June, the 24-year-old was sued by a car crash victim who claimed Duff struck her with her Range Rover.

Earlier this year, Duff announced plans to release a new studio album.