"On the road again... pregnancy after loss is whole other thing. After two miscarriages in a row we were ready to call it," the US singer wrote.
"I stopped trusting my body and started to accept the fact that I was done. As a birth attendant, I’ve seen and heard it all. It takes everything I’ve got to detach lovingly from the losses I've been present for and be in my own experience."
"When I was pregnant at 25, I knew nothing. I had no community. I dove in blissfully unaware about birth and its mysteries. Now, with 10 years worth of experience to pull from, I treasure my birth community and the knowledge I have. You're already teaching us how to stay in the day in a way we’ve never had to, little one. Thank you."
Kirke and Badgley tied the knot in an intimate courthouse ceremony in Brooklyn back in 2017.
The couple's baby news comes after You season two concluded with Badgley's character, Joe Goldberg, learning that he was going to be a father.
But off-screen, the actor has already been getting some practice in as a step-father to Kirke's son.
"He doesn't have to be 'dad' so he can have more fun with him," Kirke told Us Weekly back 2019. "It's really nice. The step-parent thing is definitely uncharted territory for me because I didn't grow up with one, but… he takes care of him really well."
Meanwhile, filming for season three of Netflix hit You is well underway as showrunner, Sera Gamble, teased the news on Twitter.
Badgley and Victoria Pedretti, who plays love Quinn, will both reprise their roles in the highly-anticipated third installment.