"I haven't really anticipated anything more than this," LANCO's Brandon Lancaster tells PEOPLE of expecting his first child, a daughter, in September
Brandon Lancaster baby announcement
Brandon Lancaster's baby announcement
| Credit: Brandon Lancaster

Brandon Lancaster's "Greatest Love Story" is about to gain one new character: a baby girl!

The LANCO frontman (who is celebrating his 31st birthday on Thursday!) is expecting his first child with wife Tiffany, the couple reveal exclusively to PEOPLE.

"It really is crazy, 'cause I've had big anticipation," Lancaster says of his excitement over becoming a dad this September. "I've played really big shows — I've played Madison Square Garden, I've played Red Rocks. I've had these incredible experiences, but I can honestly say I don't know if I've ever had anticipation and excitement for something as much as I've had for that day when [my daughter is] actually here."

"So that's been a really crazy emotion, to think that all these different things in my life that I've anticipated, I haven't really anticipated anything more than this. It's actually been really cool and grounding," he adds.

Lancaster says that he and Tiffany, 31, had their "first clue" that she might be pregnant when some candles he got her for Christmas — in varieties she usually loves — made her feel uneasy after the scents filled their home. But they didn't think much of it at the time.

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Brandon Lancaster and wife Tiffany
| Credit: Christian David Photo

Right before Tiffany officially spilled the beans to her husband, "Something was wrong, 'cause she was being really quiet," the country singer recalls. "She mentioned offhand, 'I actually have another Christmas gift for you. It's on the counter.' And I was watching The Office and kind of wasn't paying attention."

"She asked two more times, 'Um, are you gonna open this Christmas gift?' And I was like, 'Oh, yeah.' And I opened it up and it was a pregnancy test that said positive. That's why she was being quiet — because she knew she was just gonna spill the beans if I didn't open the gift!" says the dad-to-be, laughing.

The area in the couple's new East Nashville home that was going to be a guest room is now going to be the nursery — a very special space that Lancaster and his wife were in when they found out their baby was a girl.

But her moniker is another story. As the "Born to Love You" crooner explains to PEOPLE, while Tiffany "loves looking at names," he is "overwhelmed" by the number of options: "I'm kind of a procrastinator, so I think I'm gonna wait until pretty last minute and then just go with one and hope that it sticks!"

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Lancaster, who tied the knot with Tiffany on Sept. 17, 2017, is excited that his daughter is due right around their three-year wedding anniversary — something he jokes feels like "karma," as he was born on his own parents' first wedding anniversary.

"They spent all their anniversaries at Chuck E. Cheese and laser tag," he says with a laugh. "It would be kind of karma if our anniversary also ended up being a birthday party for the foreseeable future."

As far as how he thinks he will be as a dad, the singer is "so excited" and just "taking it one day at a time," trusting in the process and looking forward to "seeing the different ways" his daughter "takes after both of" her parents.

And amid the ongoing coronavirus pandemic, Lancaster tells PEOPLE it has made him and Tiffany "step back and realize what's really important in life" — namely family. "I think it's actually laying a cool foundation for the kind of parents we want to be — realizing that, at the end of the day, you have each other," he says. "You have your family. And that's the most important thing."