JACKSONVILLE, Fla. – A Florida woman suspected Chinese takeout was to blame for stomach pains over the weekend, but it turns out the culprit was actually a special delivery.

Crystal Gail Amerson initially thought there was something wrong with the General Tso's chicken she'd eaten the night before when she woke in agony Sunday morning.

Little did she know she was 37 weeks pregnant. She found out when she gave birth to a baby boy in the back of an ambulance three hours later.

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Fiance Brian Westerfield said Amerson, 29, stirred awake about 4 a.m. The couple dialed 911 when the pain had not gone away by 6:30 a.m.

"Don't eat the Chinese food," Crystal Amerson warned Westerfield as EMTs placed her on a stretcher and carried her out of the couple's home.

Westerfield said he was stunned when an EMT suggested an alternate possibility: his fiance might be getting ready to have a baby. "I turned my head so fast towards her that I got whiplash," he recalled.

Sure enough, though, Amerson delivered a 5.3-pound baby boy in the back of the ambulance just down the road from the couple's Escambia County home at 6:59 a.m.

"I didn't know what to think at first, you know. 'How does that even happen?" Westerfield wondered.

It's extremely unusual, but not unheard of, for a woman to find out she is pregnant hours before going into labor, obstetrician-gynecologist Dr. Julie DeCesare told the Pensacola News-Journal:

"Sometimes a woman doesn't have a normal menstrual cycle so they don't notice when they don't have a period. Or they use a method of contraceptive so they think they can't get pregnant, but then that method fails. Or some I've seen are just flat out in denial."

Plus, as Westerfield pointed out, his fiance did not show many typical signs when they got pregnant with their first child, 18-month-old Wyatt. In that case, they found out through a home pregnancy test.

"The whole first day, I felt like a scene from a movie that everyone's seen, where they're walking down the hall slowly and everyone is zooming past," he said. "Just a blur."

He said Amerson was released from the hospital Tuesday. Their newborn son, Oliver, is still in the Neonatal Intensive Care Unit while doctors monitor his appetite.

The couple has set up a GoFundMe page in the hopes of raising money to cover their unexpected expenses and the purchase of a new car that can fit two car seats. Click here to donate.