And judging by the ecstatic looks on their faces, the couple couldn’t be more thrilled with the news!
“You can find me on my porch, in my rocking chair, polishing my shotgun, for the next 18 to 40 years,” Nathan captioned the photo.
London, 24, also shared the snap, as well as a detailed update on how her “sweet baby girl” is doing.
Noting that she and her “lil nugget” are completely healthy, she also addressed her slender figure.
“I have 100% not strived to be skinny, but I AM striving to be healthy,” she explained. “Believe me, there has been no shortage of eating or malnutrition for me or baby girl. I know some may have seemed concerned about my size/baby's size in my mid-pregnancy photo, but I hope this helps ease some minds :).”
“We all have unique body types, and this just happens to be mine right now!” the blonde beauty continued. “It doesn't matter what size each of us are, pregnant or not, as long as we're taking care of our bodies.”
The couple shared their pregnancy news in July, with Nathan -- who is set to star in an upcoming digital scripted series, Alive in Denver -- posting a snap of the pair cradling London’s baby bump with Big Ben in the background. Later in the month, they enjoyed a pre-parenthood vacation to New Zealand, where they snapped an epic selfie in the tourist mecca of Queenstown.
This will be the first child for the pair, who both starred in the 2014 thriller Into the Storm. They tied the knot in Los Angeles, California, in 2015, but recently referred to England as their “home for now.”
See more on another famous actor about to become a first-time dad -- Kevin Hart -- below.