John and Alison Doherty, from Elderslie, Renfrewshire, discovered their numbers had come up the day before they were due to go to Florida.
Rather than take their winning ticket away with them, they hid it inside a lantern until they returned from their two-week break.
They admitted that they spent the fortnight in a "daze".
Mrs Doherty, 50, said she realised she had won after checking her numbers for the 2 July draw on her tablet.
"When I realised I had all six numbers I couldn't believe it," she said.
"I was screaming, lying on the floor, shaking like a leaf - just in complete shock".
Their first post-win purchase was a designer label handbag, which cost $400 (about £300).
Mrs Doherty said: "I love handbags but this was $400. I walked around the store for about an hour before I worked up the courage to go to the cash desk.
"I also saw someone pull up to our hotel in a beautiful Jaguar so I'm tempted to make that our new car.
"We love Formula 1 and have never been to a Grand Prix and that is definitely on our wish list along with a new house."
The holiday to Florida was a treat to celebrate their 25th wedding anniversary.
They may also have to fork out for a new car for their son, Ryan, 20, who wants a new Ford Fiesta.
But daughter, Laura, 11, might be easier to please. She wants a new goldfish.
They told a press conference that they decided to go public with their win because they're "rubbish at keeping secrets".
Mrs Doherty, a former classroom assistant at Dumbarton Primary, said: "We want our family to share in it. We want this to be nice thing."
Mr Doherty, 52, who runs JDPS Plumbers, said he was not planning to give up work yet.
He said: "I enjoy my work, I've done it for 33 years and I've got a lot of customers that I'm loyal to.
"I was out working yesterday and I'll be out working tomorrow. It's quite hard to give up."
A Scottish couple who scooped a £14m Lottery jackpot kept their win secret while they jetted off on holiday.