This video is dedicated to all the women out there who are late and ready to know the truth.

Whether it was planned or not, the only way to know before the old fashioned way is by using a take home chemistry kit that you know as a pregnancy test.

But how does a little strip of paper and a few drops of urine  tell you whether or not you’ve got a bun in the oven?

Let’s find out.

(Splash) When a woman becomes pregnant, hormones start sending chemical signals to prep the body for the tiny person who will be taking up a nine month residency inside.

One of the first hormones produced is human chorionic gonadotropin, or hCG for short, and this is what pregnancy sticks are designed to detect.

Pregnancy tests have three main sections: the place to pee on, the place where the main chemistry happens, and a control to make sure you can be confident in the results.

There’s some pretty tricky chemistry that goes on during the test, so what we’re going to do is show you both a positive test (test1) and a negative test (test 2) side by side for comparison.

After pee is applied to the first part of the test stick, capillary action causes it to slowly flow through to the other end.

First it passes through a thin strip loaded with mobile antibodies that are taken up by the pee, and are designed to bind to hCG.

These antibodies are also equipped with a special piece of cargo that’s put to use later on in the test, but we’ll come back to that later.

If hCG is present like in test 1, the antibodies start binding to it, and move through the test as a unit - unlike in test 2, where the antibodies move through on their own.

At this point, you can’t actually see anything happening.

But that’s about to change as the pee flows to the next section, which we here at Reactions like to call the antibody test-forest.

Each individual tree in the test-forest is an antibody rooted in place that’s specially designed to grab onto a different part of the hCG.

So when the pee in test one passes through, the hCG-antibody pairs get trapped in the branches of the test forest, where that extra piece of cargo comes into play.

And as more and more hCG-antibody pairs get stuck in the forest and begin building up, that dye becomes more and more visible to the naked eye.

And that’s the blue line you see if you’re pregnant.

-  The urine in test 2 on the other hand, with solo mobile antibodies in it, flows right through the test-forest undetected.

But that leaves test 2 a bit high dry, don’t you think?

How can they be sure that say, their test strip wasn’t ripped, cutting off the urine from reaching the antibody forest, or that the mobile antibodies really were taken up by the pee?

For this reason, manufacturers add a control -- another antibody forest downstream from the first one, that we’ll call the control-forest.

The control-forest is exactly like the test-forest, except instead of having antibodies designed to detect hCG, they’re actually designed to detect the mobile antibodies!

So in both test one and test two, the branches of the control-forest grab onto the mobile antibodies.

As they build up the dye on the special cargo becomes visible, and the control line appears.

All functional pregnancy test should have the control line appear.

If it doesn’t, it means something messed up the test result, and you’ll have to try again.

If both lines light up, there is a 99%+ chance you’re pregnant.