The actress made the announcement by sharing a post on Instagram.

This was welcoming news for the actress who had reportedly suffered a heartbreaking miscarriage earlier.

Fox shared an image of her baby bump on Instagram.

"Nothing is ever really lost. Welcome back," she wrote on Instagram.

Along with an image of herself, the actress also shared a picture of the positive pregnancy test she underwent recently.

This is going to be Fox's fourth child.

She is already mother to sons Noah, 12, Bodhi, 10, and Journey, 8, with ex-husband Brian Austin Green.

Her partner is going to be a father for the second time.