Livingston, who welcomed son Charlie Ocean Goldblum on July 4, captioned the collage of photos, including one marked "8 days after" showing off her flat midsection.
"#fbf to my day before giving birth to Charlie picture! I can't believe it's already been 13 days and that tomorrow he'll be two weeks! We're in perpetual awwwe and blissfully content with our Charlie! #charlieoceangoldblum," the new mother wrote.
Livingston, who appeared on the "Kroll Show" in 2014, kept her Instagram followers up to date throughout her pregnancy.