Is It Okay To Take a Pregnancy Test at Night?

woman sitting in a chair by a bright window

Think you might be pregnant? It is about 9:00pm right now? Do you have a pregnancy test in your hand that you just purchased for $7.99 at the local grocery store? (Maybe it is a two-pack).

Maybe you don’t have the test in your hand, but you are surfing the net, thinking about jumping in the car to go get one (instead of waiting until tomorrow).

You may have heard (or the box might even say) that the best time to take a pregnancy test is in the morning.

You might want to know the answer to the question that has been plaguing you for the past few days. (Maybe you are dreading the answer)

You might want to know if all the work you’ve been putting in for the past few months (or even years) has FINALLY borne fruit.

The question is… I pregnant?

First, let’s talk about why it matters WHEN during the day you take the test.

To understand the answer to the question, the first thing you need to do is understand how a pregnancy test works.

In general, when you buy a pregnancy test from the grocery store, you have bought a test that measures the amount of a certain hormone in your body that is only produced when you are pregnant. This hormone is detectable in your urine. The test is usually a plastic stick-like device, and you are supposed to pee on the end, put the cap back on it, and then wait for a few minutes.

(I was always a little anxious about peeing on the stick just right, and not getting an accurate result because of my pee, so I always peed into a cup, then stuck the stick into the cup to make sure the pee covered the stick sufficiently and uniformly).

What hormone does the stick measure?

The hormone is called hCG, human chorionic gonadotropin. It is produced by a woman’s placenta.

hCG is not detectable until several days after the egg is the woman’s body is fertilized, as it takes time for the fertilized egg to attach to the uterine wall and for the placenta to start to grow and form.

The home pregnancy test can only reveal the existence of hCG in your pee, but not how long it has been there or how much there is in your pee.

Okay, okay, I get it. It measure the existence of the hormone. Why does it matter when I take the test? If the hormone is going to be there in the morning, shouldn’t it be there at night?

The test is not necessarily as sensitive as the tests that will/would be performed at the doctor’s office. There is a threshold amount of the hormone that must be detected in the urine before the little line (or x or + or whatever the test reports) becomes visible for you. It is possible that you can be pregnant, and the test fails to show you a positive result because it there just isn’t enough hCG in your pee.

How would that happen? Shouldn’t the amount of hormone be consistent?

The concentration of stuff in your pee (hormones, waste, other things your body wants to get rid of) depends upon how hydrated you are. If you have been drinking a ton of water during the day, the amount of the hCG hormone in your pee is going to be diluted, and harder for the pregnancy test to detect.

And taking the test at night is a problem because…

There is a risk that the test won’t detect the hCG in your urine because you spent the entire day doing the things you would normally do, which would likely include consuming foods with liquid in them, or drinking liquids (such as water, milk, soda, coffee, tea, etc).

The morning is recommended because…

It is recommended that you take the test in the morning because, if you went to bed 7-12 hours before, it is unlikely that you drank fluids during that period of time, leaving your urine the most concentrated it will be all day (of the hCG hormone, and with all the rest of the stuff your body worked on getting rid of during the night).

And the risk of taking the test at night?

The people who make and sell pregnancy tests sell them to you with the marketing promise that the tests are accurate. The best chance of the test being accurate is if a woman takes the test in the morning.

If a woman takes the test in the evening, the chances are increased that the pregnancy test will show a negative result, when in fact the woman IS pregnant, and would have received a positive result if she had waited until taking the test in the morning.

The earlier it is, the more this matters.

The amount of hCG in your body once the egg has been fertilized ramps up over time. In the beginning, when there is little hCG in the body (and pee), the chances of receiving a negative result is higher than if the body is given more time to develop the pregnancy.

In the beginning, when hCG levels are low, it will definitely matter more when during the day you take the test. But at some point, it isn’t going to matter because the hCG levels will be high enough to be detectable, no matter how much water you drink.

Can You Get Pregnant a Week Before Your Period

Okay, so I can’t wait. I want to take the test RIGHT NOW.

The take the test! Buy a two-pack at the store (I see them BOGO all the time), and then take one tonight. If the result is positive, then you don’t have to worry about taking the test again in the morning, as the morning test won’t make a different.

But if the result is negative, you will probably only be able to put this question to bed until after you’ve taken a test in the morning.

And here’s the thing….if you are really early in your pregnancy, it might not make a difference if you take the test in the morning or at night. If there isn’t enough hCG, then the test won’t provide a positive result until there is.

If you suspect that you are pregnant, but get a negative result in the morning and at night, you might just want to sit back and wait a few days and then try again. If you feel pregnant, and the tests keep coming back negative, it is probably time to reach out to your doctor.

How do I prepare for taking a home pregnancy test?

Not much to do here. Read the box. Follow the step by step instructions for how to take the test. Check to see how old the test is.

If you can do it, try to take the test first thing in the morning, with the urine from the first pee of the day.

Then wait and see what happens.

Is there anything that can cause a false positive or a false negative?

Sure. I’m not a doctor, so don’t take this advice as such. All results from any pregnancy test can be confirmed by a doctor.

But as we discussed before, dilute urine could cause a false negative (but not a false positive).

Certain medications like antihistamines can cause a false negative.

Other medications, such as anti-convulsants, hypnotics, tranquilizers, can cause false positives.

It is night time. I took the test and I’ve waited several minutes, but the test is still negative.

You might not be pregnant. Or your pee is too dilute. Or it is just too early to tell.

If you think you are pregnant, try again in the morning, or wait a week and then try again.

And if the test is positive?

It’s time to call your doctor.

Wrap Up

If you are thinking you might be pregnant, I would just recommend that you take steps to find out. I know that I couldn’t wait to know, one way or another, and I took pregnancy tests that ended up being negative. But just having the answer made it so much easier for me to go about and do the things that I needed to do, instead of sitting at home and just worrying about it.

If you have any other questions about using a pregnancy test at night, let us know in the comments section below.

All the best.

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