Karla Hornby and Jordan Jackson were by the pool on holiday in Benidorm last Saturday when her waters broke.
She was taken to San Juan Hospital in Alicante where she gave birth to son Freddie by emergency caesarean section after his heart stopped beating.
Ms Hornby said it was a "nightmare" but Freddie who weighs 2lbs was doing well.
The 29-year-old said she and her partner, from Breightmet, were planning to have a week away to relax and she had been told she was OK medically to fly.
She said: "We didn't think it would be a problem. It was only two hours away [on a plane] and only a week but then my waters went at the side of the pool.
"I couldn't believe it, I was in total shock.
"He's absolutely beautiful, he's perfect but he's just so, so small. He's only 2lbs but he is only on a tiny bit of oxygen, he's not on anything else, no antibiotics or anything.
"He is doing so well."
"Hopefully he should put on weight soon and we can get him fat and bring him home."
Insurers have agreed to pay medical costs and for a hotel but Ms Hornby is having to use a wheelchair and said the accommodation was too far away from the hospital.
Her best friend Lisa Johnston, who said it could take at least three months for Freddie to be strong enough to take him home, has started fund-raising to help with the couple's living costs including finding a hotel nearer the hospital in the meantime.
Some women choose not to travel in the first 12 weeks of pregnancy because of the exhaustion and nausea they experience. The risk of miscarriage is also higher in this stage of pregnancy.
Most airlines will not allow women to travel after week 36 of pregnancy, or week 32 if they are pregnant with twins or multiples. This is because the likelihood of going into labour is higher.
Women are advised to check with their airline and insurance company that they will allow them to travel while pregnant.
Source: NHS Choices
A couple from Bolton whose baby was born 12 weeks prematurely on holiday in Spain have said they could be stranded in the country for three months.