The 32-year-old actress gave birth to her first child -- a baby girl -- with her boyfriend, Matte Babel.
Mitchell announced the news with a photo she posted to Instagram on Sunday. The excited new mom shared a heartwarming snapshot of her newborn daughter's tiny hand reaching out and grasping her finger tip.
Mitchell captioned the touching photo simply, "Never letting go..."
Many of Mitchell's friends and fellow celebs excitedly celebrated the big news, congratulating the couple on the new addition to their family -- including her Pretty Little Liars co-star Ashley Benson, who commented, "Congrats angel. Love you. Can’t wait to meet the baby booooo."
"I chose to hold on until I announced because of the first time," she said. "It didn't go as I had hoped for, and it was extremely difficult. The first time that I was pregnant last year, Matte and I hadn't been planning, it happened and we were really excited about it. I was like, 14 weeks. At that point, I had no idea the percentages of miscarriages."
"When it happened, I was just completely blindsided by it," she continued. "I still have those photos on my phone. I still have all the doctor visits, and it's weird because I haven't looked at them, obviously, but it's not like I forgot about that happening. Of course, I’m, like, super happy, but I still feel for that one that I lost. ... It's just really tough because you feel broken as a woman, and that's not a great feeling."
Mitchell also got emotional about not being able to do the things she was used to -- like going out as well as pushing herself to the limits when it comes to exercising -- and at one point, cried by herself in her car.
"This is the shi**y side of being pregnant when nobody knows because you can't go out to see anyone, you don't want to see anyone, because, anyways ... I don't feel myself," she said.
Of course, Mitchell has experienced more lighthearted moments during her pregnancy, including her incredible dancing while trying to induce labor.
"I'm officially overdue and trying everything.... dancing, extra spicy Prince Street pizza, turmeric ice cream (although Matte seems to be having more of it than I do)," she wrote about her YouTube video on Oct. 10. "If the Baby Mama Dance won't work, what will??"
For more on the former Pretty Little Liars star's pregnancy journey, watch the video below: