When can I take a Pregnancy test?

When you are trying to conceive, it can be an emotional and anxious time. This is magnified if you have been through a miscarriage or pregnancy loss. With a variety of pregnancy tests on the market, the decision of when to test can be confusing. When is it too soon to test? If it’s days past my expected period: is it too late to get a positive? Here’s what you need to know about pregnancy tests, including how they work, which kind is best, and when to take them.

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Table of Contents

What is a Pregnancy Test?

A pregnancy test looks at the levels of the hormone Human Chorionic Gonadotropin (hCG) in the urine or blood. Serum hCG tests can be ordered by a physician and are done in a lab using a blood draw to detect pregnancy. Urine tests are the over-the-counter, home tests that many of us are familiar with. A urine test can be a stick or a strip. It can be held in the urine stream or dipped in urine depending on the type and the manufacturer’s instructions.

What level of hCG is needed for a positive pregnancy test?

It’s hard to get a clear answer to this question, largely because each type of test is different. There are some generalizations we can make though to help answer this question.

Serum hCG tests (blood tests)

Serum hCG tests for pregnancy are the most sensitive. This means that they can detect a low amount of hCG, and are the first kind of test that may show a pregnancy. Serum hCG tests also show the amount of hCG in the blood (as opposed to urine tests which are only positive or negative).

An hCG level of less than 5 mIU/mL is negative for pregnancy.

Between 6 and 24 mIU/mL is unclear. Your provider may order another test to see if levels rise before confirming pregnancy.

An hCG level of 25 mIU/mL or more is positive for pregnancy.

Urine tests (over-the-counter home tests)

Urine tests vary in the level of hCG that they are able to detect. You may be able to find the hCG level for that test listed in the information in the package, but not always. These home pregnancy tests are either positive or negative.

Positive pregnancy test

A positive pregnancy test means that you are pregnant. There is very little chance that a positive pregnancy test is wrong, but there are a few cases where that could happen. First, never read the pregnancy test after the time limit in the instructions. There may be an evaporation line that could be confused as a positive pregnancy test. Read the directions carefully. An expired pregnancy test could also give a false positive. Also, if you recently had a miscarriage, pregnancy loss, or gave birth, you could get a false positive pregnancy test. This is because your hCG levels may not yet have returned to normal.

If you have concerns about a possible false positive pregnancy test, please check with your healthcare provider.

Negative pregnancy test

A negative pregnancy test means that you are likely not pregnant. It is more likely to have a false negative pregnancy test than a false positive one. That means that even if you had a negative pregnancy test, it is possible that you could still be pregnant. This is because the levels of hCG vary widely in pregnant women. Also, there is quite a bit of variability of normal menstrual cycles. We’ll discuss that variability more in the next section of this article.

For now, just know that if you are testing before or on the date of your expected period, you could get a false negative. Most tests now claim a 99% or better accuracy on the day of your missed period. Even so, there are women who ovulate later or take longer for implantation to occur. This could result in a false negative test on the day of their missed period. If you think you are pregnant, consider taking another test 2 days later.

What hCG levels can be detected by pregnancy tests?

Easy@Home test strips claim to detect hCG levels as low as 25 mIU/mL. This is fairly common for a regular at-home pregnancy test.

Clearblue Early Detection pregnancy tests state their test sensitivity is 10 mIU/mL. They claim to be able to detect a positive pregnancy as early at 6 days before your missed period.

This kind of difference in test sensitivity can make a big difference in your decision of when to start testing. If you can, take a look at the packaging or online to see what level of hCG your pregnancy test will detect.

How do I know when I should start testing?

After conception, the fertilized egg travels to the uterus and implants on the uterine wall. A placenta will then begin to form, and this causes hCG to be produced. There are a few ways to guess when this occurs and when hCG levels will be detectable for your over-the-counter pregnancy test. You can either guess based on the first day of your last period, or if you were testing for ovulation, you can use the number of days past ovulation (DPO).

It is important to understand, that no matter which method you use, this is still a guess. Cycles vary and our guess may be off a few days from what actually happened. Ovulation testing will give you a more accurate idea of the timing. However, the amount of time from conception to implantation can also vary. Let’s take a closer look.

When to take a pregnancy test based on first day of last period

Per the Cleveland clinic, a healthy menstrual cycle is 24-35 days. Since each test is different, the best way to know when to test is based on the recommendations of the brand of test you are using.

For an early test, like Clearblue Early Detection pregnancy tests, you may be able to test 5 days before you expect your period. With a regular pregnancy test, it’s usually recommended to test on the day of your missed period. This means that you would test the day after you expected your period. For example, if you had a 28 day cycle and the first day of your last period was February 1st, then the day you expect your next period would be March 1st. That means you should test on the day of your missed period, which would be March 2nd.

If your cycle varies…

With a variable cycle, it’s a bit harder to predict. You can choose to do one of two things. If you don’t mind using extra pregnancy tests, and want to know as soon as possible, take a test based on the date of your shorter cycles. Realize that even if it is negative, you could still be pregnant. That’s because, if you ovulated later, your hormones haven’t had a chance to rise to detectable levels yet. You should keep testing, possibly every other day to give time for hCG levels to rise. In the early days of pregnancy, hCG levels tend to double every 48 hours.

If you don’t want to spend money using a lot of pregnancy tests, wait the length of your longest cycles before testing. It may also be better to wait to test if you feel that you will be negatively affected emotionally if you get a false negative early and later find out you were pregnant all along.

When to take a pregnancy test based on Ovulation testing

When you are testing for ovulation, it is a bit easier to predict when you could expect a positive pregnancy test. Ovulation testing does still have an amount of variability. For example, when you test for ovulation you are actually testing your luteinizing hormone (LH). LH peaks roughly 24-48 hours before ovulation. Then, the amount of time it takes for the fertilized egg to travel to the uterus and implant varies from 6-12 days after ovulation, although normally it is 8-9 days.

How does the date of ovulation help for pregnancy testing?

Once you know when you likely ovulated, you can use the number of days past ovulation (DPO) to determine when to test for pregnancy. With an early pregnancy test like the Clearblue one mentioned above, you may be able to get a positive as soon as 9-10 DPO. With a regular pregnancy test that recommends testing the day of your missed period, start testing at 15 DPO. Since there is a bit of variability even when testing for ovulation, retake a test two or more days later if you think you may have had a false negative pregnancy test.

I personally like ovulation testing. This is not just for trying to conceive (TTC), but actually for more accurate testing and dating for pregnancy. I tend to ovulate later in my cycle, and since my first miscarriage I have had shorter menstrual cycles. If I went off the first day of my last period, I would be testing too early. I could maybe have false negative tests. With ovulation testing, I know that I actually should only begin to take pregnancy tests about 3 days after my expected period. And don’t worry about me; I’ve been working closely with my providers regarding my messed up menstrual cycle but the recurrent miscarriages have been a challenge.

Can I take pregnancy tests early? Can I take a pregnancy test every day?

Truthfully, how early and how often to test can be a very emotionally charged decision. Sometimes, especially after pregnancy loss, the facts are less important than the emotions and anxiety. I want to encourage you to do whatever will make you feel better. Sometimes I’ve been able to wait. Sometimes I just took early tests every day (or more than once a day) because I had to know as soon as possible for my own sanity. If you’re thinking about testing early, here’s my list of pros and cons. This way, you can make a good decision for yourself:

Reasons not to test early and often

Testing early is more likely to give a false negative result. Seeing a false negative result can be disappointing when trying to conceive
You will use a lot more tests, which can be expensive. Early pregnancy tests are particularly expensive.
Testing early doesn’t give you peace of mind that the pregnancy is going to go well. In fact, there is limited early testing that your provider can do, besides taking serum hCG levels and progesterone levels. If you are going through pregnancy after loss, early testing lengthens the agonizing wait until an ultrasound is done.

Reasons to test early and often

You will know that you are pregnant as soon as it is possible to know.
If you purchase a large box of test strips, testing frequently can be easy and more affordable
If you have medical concerns that may require medications when you become pregnant. Early testing lets you tell your provider about your pregnancy as early as possible
If testing early and often will give you peace of mind. Sometimes, anxiety is less when you feel free to take a test whenever you want. On the other hand, taking tests and getting a false negative can worsen worries and anxiety. This is a very personal decision, and may even change from month to month or pregnancy to pregnancy.

I’ve missed my period, but got a negative pregnancy test. Should I keep testing?

Because of the variability of menstrual cycles and hCG levels during pregnancy, it is possible to get your first positive pregnancy test days after your missed period. If you haven’t had your period yet, consider testing for pregnancy again. Once you are several weeks past your missed period and you still have negative pregnancy tests, contact your healthcare provider. If you have unpredictable menstrual cycles, or PCOS, and you’re concerned, talking with your healthcare provider is still the best thing you can do. They can give you more specific advice tailored to you.

I hope this helps you as you make your decisions about when to test for pregnancy. Use this information to help you understand what to expect. Then feel free to make whatever decision will bring you peace of mind.