Rachel Houlihan

The test works a bit like a jigsaw puzzle. Thousands of pieces of the unborn baby's DNA need to align perfectly with thousands of pieces of paternal DNA for it to be a positive match. If the puzzle pieces don't line up, the test will come back negative. You're not the dad. If the pieces sort of match up in a few places but mostly don't, it will come back as inconclusive.

The test works a bit like a jigsaw puzzle. Thousands of pieces of the unborn baby's DNA need to align perfectly with thousands of pieces of paternal DNA for it to be a positive match. If the puzzle pieces don't line up, the test will come back negative. You're not the dad. If the pieces sort of match up in a few places but mostly don't, it will come back as inconclusive.

But a false positive, a test saying you're the dad when you aren't, the chances of that happening are basically zero. It's a very accurate test. In 2015, when John goes looking for the test, the technology is still pretty new. Lots of companies are popping up offering the test. The one John and the mom-to-be choose is like a DNA test broker. It farms out the actual testing to another company.

But a false positive, a test saying you're the dad when you aren't, the chances of that happening are basically zero. It's a very accurate test. In 2015, when John goes looking for the test, the technology is still pretty new. Lots of companies are popping up offering the test. The one John and the mom-to-be choose is like a DNA test broker. It farms out the actual testing to another company.

This will end up being important, though the couple doesn't know it at the time. But they do know it's going to be convenient with an at-home sample collection service.

This will end up being important, though the couple doesn't know it at the time. But they do know it's going to be convenient with an at-home sample collection service.

We hear this over and over and over again while researching this story. Pivotal moments where people don't trust their gut. And I get it. They're feeling vulnerable. Their entire future is in question. And they need answers. So they set their misgivings aside. And they put their trust in the only thing that makes sense in that moment. The science.

We hear this over and over and over again while researching this story. Pivotal moments where people don't trust their gut. And I get it. They're feeling vulnerable. Their entire future is in question. And they need answers. So they set their misgivings aside. And they put their trust in the only thing that makes sense in that moment. The science.

Besides, by this point, John's around a thousand bucks in.

Besides, by this point, John's around a thousand bucks in.

And so they wait for two agonizing weeks.

And so they wait for two agonizing weeks.

John and the mom-to-be line up a three-way call.

John and the mom-to-be line up a three-way call.

A match. It's said so casually, John's in shock.

A match. It's said so casually, John's in shock.

So the company emails the result. And at the top of the page, in bold letters, the name of the lab that did the test, Prenatal Paternities, Inc.

So the company emails the result. And at the top of the page, in bold letters, the name of the lab that did the test, Prenatal Paternities, Inc.

At 21 years old, John is going to be a dad.

At 21 years old, John is going to be a dad.