Megan Fox is reportedly pregnant with her first child.

The 25-year-old actress and her husband Brian Austin Green are expecting their first child together, reports Star magazine.

According to the publication, the couple are thrilled with the "unexpected" news.

"They just found out and are incredibly excited," a source close to the couple told the US magazine.

Despite the reports, it is unlikely the couple will announce the pregnancy as it's still early days. According to the source, they are keeping the news close to their chests for the time being.

"It's still early, so they are only telling close friends and family members," the insider revealed.

Megan and Brian tied the knot in a private ceremony in Hawaii in 2010. The brunette beauty has become a maternal figure to Brian's ten-year-old son, Kassius from his previous relationship with Vanessa Marcil.

According to the insider, Megan who has been involved with Brian since 2004 is thrilled to be expecting a child of her own.

"Megan has become a great stepmom, and Brian knows she'll be wonderful with the baby," the source said. "She has really grown in the past couple of years. Megan used to only be concerned with her career, but now family comes first."