"We have felt your support," the actor, 28, wrote on Instagram Monday. "We are taking things positively and moving forward with our future. It's hard but we are not alone. Thank you for respecting our privacy. We will be expanding our family soon."
The couple shared the sad news about the loss of their "miracle baby" in a joint statement on Instagram on Saturday.
"Perhaps we should have waited to announce until we were further along," the message read. "However, we were overly excited to share the good news" when it was announced in April.
Sam's message thanking fans for support came an hour after Britney, 40, posted a throwback video of herself at the beach during a recent vacation in Mexico. In the vid, she's playfully running around with her top off but her hands over her chest.
While many of the comments were supportive ("I hope you are feeling well, Britney," was one), others were not ("Didn't you just lose your baby? This is disturbing") — yet another reminder that the internet can be a mean place.
Britney's pregnancy announcement came less than a year after the pop star emotionally declared in court that she wanted more kids but her 13-year conservatorship, overseen by her estranged father Jamie, forced her to be on birth control. She already has two sons — Preston, 16, and Jayden, 15, — with ex-husband Kevin Federline.
Britney and Sam, who started dating in 2016, became engaged in September. Two weeks later, her father was ousted as conservator and the conservatorship ended in November. The star remains estranged from her entire family, saying she wants to sue them for the conservatorship. She's currently writing a book about her conservatorship ordeal.