Danielle Olivera has officially entered her mama era -- 'cause the former "Summer House" star has announced she's pregnant!

The reality star dropped the happy news Friday with a sweet IG post featuring BF Eoin Heavey cradling her baby bump ... captioning the snaps, "Baby Heavey on the way 🐣✨🥹."

Danielle was absolutely glowing while showing off her growing bump ... with fellow Bravolebs flooding the comments with congratulations, including Olivia Flowers and Leva Bonaparte.

The baby update comes nearly two years after Danielle announced she was leaving "Summer House" ahead of Season 9 ... calling it a heartbreaking decision at the time.

Turns out trusting her gut worked out pretty well ... Danielle has since been focusing on her relationship with Heavey, who she started dating about a year ago after knowing him for quite some time.

Big congrats to the parents-to-be!