"I'd never really gone through labor because both my babies were C-sections because of complications with my pregnancies," the mother of three reveals in a video posted to her YouTube page on Thursday. "I thought for sure this is going to be a C-section."
After securing a babysitter for their older children, 4-year-old Brooks and 1-year-old Scarlett, Sims and husband Scott Stuber rushed to Cedars-Sinai Medical Center in Los Angeles.
"I can't tell you how stressed I was," she confesses. "I was trying to make my husband go through red lights on Sunset [Boulevard] because we live quite far from Cedars. We got into an argument because he wouldn't run a red light, because I was having contractions."
Once they arrived at the hospital, Sims attempted to convince the doctors that she wasn't actually in labor, and could "hold off" until the next day.
"Nevertheless, I was in full-on labor," she recalls while cradling the newborn, and thanking the team of nurses for their hard work.
"It's crazy to watch those nurses and what they do, and how quickly they get in," she says before gushing over her son. "He's been fantastic."