Stephen Cooke walked into the Georgia Lottery office in Atlanta on Wednesday morning thinking he’d won $13 million.

He walked out with a check for $26.6 million.

The 60-year-old school bus driver from Roswell had two of the three winning tickets for the $70 million jackpot and didn’t know it.

He said he didn’t bother looking at his other tickets when he realized he’d won the jackpot with one.

“The Georgia Lottery people kept querying me about what place I bought my ticket and what time,” Cooke said. “I thought that was strange. I already had a winner.”

What lottery officials didn’t tell Cooke right away was that they knew two winning tickets for the jackpot had been purchased at the same time and same place — the SaveRite at 10800 Alpharetta Highway in Roswell.

They suggested he return home and check his other tickets.

So Cooke was escorted home by a Georgia Lottery security guard to get his other tickets. In fact, he also had two $150 winning tickets using a combination of relatives’ birthdays.

But the news that he was a multiple winner “didn’t matter,” Cooke said.

“It’s already astronomical,” he said. “I hope I’ll never spend $13 million. That’s more money than I need.”

The winning numbers for Tuesday’s Mega Millions drawing were 02-05-17-21-22 and the Mega Ball was 43. Cooke said he played his and his mother’s birth dates and didn’t realize he’d used the numbers on both tickets.

Cooke won two-thirds of the $70 Mega Millions jackpot and got $26.6 million after choosing the cash option instead of having the payout spread over 30 years.

He would have received more money over that time period “if I had lived that long,” he joked.

Cooke said he has no children and is not married “for now.”

He has worked in sales and was a manager at a bottled water company. He recently finished training as a Fulton County school bus driver because he wanted to work with kids and the school system has an excellent insurance program, he said.

The third winning ticket was sold in Portage, Mich., but had not been claimed by late Wednesday. Michigan is one of 10 states that take part in Mega Millions drawings.

At the SaveRite grocery store in Roswell where Cooke purchased the tickets, assistant manager Liz Watson said a lottery worker who came in Wednesday morning to run a sales report mentioned the store might have sold the winning tickets.

But she said employees had been too busy Wednesday changing prices to reflect the week’s specials and taking care of other business to celebrate their customer’s good fortune.

“So far I don’t think the word’s quite gotten around yet,” she said.