A New England couple's lives were turned upside down when they unexpectedly welcomed a baby boy into the world hours before they were due to set sail on a cruise.

Gary 'David' Glenn and Lauren Siwinski arrived in the Tampa Bay area to visit friends before a five-night trip to Mexico when the mom-to-be experienced severe abdominal pain and was rushed to the emergency room at HCA Brandon Hospital. 

That's when Siwinski - who was on birth control and had no prior signs of pregnancy - received the shock news: she was already in labor. 

'He comes back, and he goes, ‘You guys are pregnant.’ And I’m like, ‘Is she...what?’ You feel like you’re pinching yourself, and you’re like ‘What are you talking about? This isn’t real,’' Glenn told WBTV. 

Hours later, instead of being on board the Royal Caribbean ship, Siwinski gave birth to a healthy baby boy called Sebastian, who family members have jokingly nicknamed 'Cruise.' 

'Sometimes life has a way of changing every plan in the most beautiful way,' HCA Brandon said in a Facebook post. 

'This little boy may not have made it onto the cruise, but he'll forever be the best vacation souvenir his parents could have ever brought home,' the post continued.

The hospital shared photos of the new parents doting on Sebastian, with many on social media wishing them well.

'Congratulations to the unexpected parents,' one user wrote. 

'Oh what a surprise! Congrats!' another added.

Others voiced their surprise at the hidden pregnancy story. 

'It’s crazy how our bodies work! Cryptic pregnancies are so fascinating to me. Congrats,' another said.

For now, the parents, who got engaged in May, will remain in The Sunshine State as they wait for Sebastian's birth certificate.

'I was like, ‘I don’t know what I’m going to do, how I’m going to afford this,’' Siwinski told WBTV. 'But the more support we get, the better and better I feel.' 

Cryptic pregnancies are uncommon, according to the Cleveland Clinic, with studies suggesting about 1 in 2,500 pregnancies go unnoticed until delivery.