That's all it took for Lewis McIntosh to pop into the world in the back of an ambulance last Sunday, delivered by paramedics on the way to hospital.

In fact, from heading home mid-supermarket shopping at 3pm on Sunday afternoon to baby Lewis arriving was a little over two hours.

Dad Andrew McIntosh said Lewis, who's the couple's third child, didn't waste any time coming into the world, throwing their plans into disarray.

"We went shopping at 3pm and Tara had a few contractions and we thought 'it's coming, we better get home and get into gear'," he said.

"We called Tara's sister who was going to look after the boys to get her to come over."

Knox, age six and Owen, age three, didn't have to wait long for the third member of the family to come along - Mr McIntosh called the hospital at 4.30 say they were on the way, by 4.40 the ambulance had arrived and less than 15 minutes later he was out.

"Everyone was a bit shocked at how quick it was, Knox was 24 and a half hours, Owen was two hours and Lewis was about 20 minutes," Mr McIntosh said.

"I guess he just wanted to meet his brothers."

He said mum and the new bub was "doing well".

"He's doing all the right things, putting on weight, sleeping, crying, pooping ... we're all real good."

The family was able to thank paramedics in person last week, too, visiting the ambulance depot to meet outside the frantic rush of the birth - and giving Knox and Owen the chance to play around.

"They loved it, getting to run in and around the trucks," Mr McIntosh said.

"It was great to be able to find out who [the paramedics] were as people as opposed to them doing their jobs."

Paramedic Katie McLean was the one who delivered baby Lewis into the world, and said despite all the training done to ensure she was ready, it was still an 'exciting' experience delivering a baby for the first time.

"It's the most amazing thing you can do in this job, it's a lot of excitement," she said.

Mrs McLean said it happened so quickly, with the ambulance leaving the McIntyre house at 4.43, Lewis crowning at 4.45 on Forrest Road and arriving before reaching the hospital.

"We pulled up at the hospital to a crowd of midwives and doctors and they expected to take Tara in and instead were greeted with me with a big smile on my face holding the baby," she said.

Mrs McLean, who's worked as a paramedic for three years in Newcastle, Gilgandra and Molong, said it was lovely to meet the family again.

"Really good, we don't often get a chance to follow up on our patients so it was good to see them again," she said.