Can I trust my pregnancy & ovulation test results?
Written by Jamie Norwood
June 22, 2020 • 7 minutes
Testing for pregnancy can be stressful. Buying pregnancy and ovulation tests can be expensive, knowing how and when to take them is confusing, and wondering if your results are accurate is frustrating.
How do I know if I can trust my pregnancy and ovulation test results?
Let’s get into some information that we found helpful regarding the accuracy of your test results.
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When should I take a pregnancy test?
Stix can detect hCG at 20mIU/hCG, or about 7 to 10 days after ovulation. For the best results though, we do recommend taking the test at least three days before your missed period or 19 days after you had sex. Your levels of hCG increase every single day so the longer you wait to test, the stronger the results will be.This will produce the most accurate results because shortly after a fertilized egg attaches to your uterine lining, the placenta begins producing a hormone known as human chorionic gonadotropin, or hCG. During the first few weeks of pregnancy, the hCG concentration doubles every two or three days, so the earlier you test, the harder it will be for the test to detect hCG in your urine. It can be hard, but getting in the know about when to test promises more accurate results.
Taking a pregnancy test first thing in the morning will also raise the accuracy of your results. Why? Your urine is much more concentrated in the morning, before you drink any water, which makes it easier for tests to detect levels of hCG. After you’ve had a glass of water, your pee becomes diluted and hCG levels may appear lower than they are.
False-positive and false-negative results do happen. Though most pregnancy and ovulation tests are over 99% accurate, there are certain factors that go into testing that can mess with the accuracy of your results.
False-positive pregnancy test results can be caused by a number of things. Oftentimes, pregnancy tests produce evaporation lines that makes the result a bit less clear. To avoid evaporation lines, read and follow the instructions about when to look at your results after taking the test. Stix provides easy-to-follow instructions with clearly defined lines so that you don’t second guess your results. Also, false-results are likely if the test is expired, so be sure to check the expiration date before testing!
Next, the medications that you take could be to blame for false-positive results. For instance, you may be taking fertility medicine called a synthetic hCG trigger shot. This medicine works by helping follicles produce mature eggs and can lead to false-positive pregnancy test results. Other medications that can cause false-results include anti-anxiety medicine like Xanax, antipsychotics, diuretics, and Parkinson’s disease medicine.
False-positive results are also caused by chemical and ectopic pregnancies. A chemical pregnancy happens when an egg is fertilized, but is unable to implant and grow. This is a result of issues within the uterus that are beyond our control. An ectopic pregnancy is when a fertilized egg implants itself outside of the uterus, usually living in the fallopian tube. This can be caused by scar tissue in the fallopian tube or past uterine infections.
Finally, if you’ve recently had a miscarriage or an abortion, it’s likely that a pregnancy test will show a false positive. This is because levels of hCG, which is the hormone that pregnancy tests pick up, can stay in your body for several weeks after. While hCG levels decrease once pregnancy ends, it is a very slow process and can take up to six weeks for your hormone levels to return to normal.
False-negative pregnancy test results occur when the test shows a negative result but you are in fact pregnant. This is sometimes the result of “the hook effect”. The hook effect happens when blood or urine contains too much of the hCG hormone that the pregnancy test is too overwhelmed to produce a positive result. Excess levels of hCG are common if you are pregnant with twins or triplets, as each baby is making the hCG hormone rather than just one.
Nobody can keep all false results from happening. But, knowing when and how to take them, as well as some likely causes of inaccurate results, can help bring some peace of mind. Consulting a doctor can clear up any questions with your results..
Similar to pregnancy tests, ovulation tests can produce inaccurate results if you don’t have a grasp on what is happening in your body. Ovulation tests are useful if you’re trying to get pregnant as they help track your cycle so that you can plan sex around your fertile window. Tracking ovulation is also beneficial if you’re not trying to conceive, as it allows you to avoid sex when you are most likely to get pregnant. If you don’t know how and when to properly test, however, it can be hard to know how accurate your results are and easy to miss your ovulation window.
When Should I Take an Ovulation Test?
Ovulation is not like clockwork, and figuring out how to track it can be difficult. While predicting your period has been made possible by menstruation tracking apps, taking an ovulation test can help you predict even further into the future.
Ovulation happens once a month and only for a 12-24 hour window, sometime in the middle of your menstrual cycle. For this reason, it’s best to start testing a few days before your midway point. To help figure out when this is in your cycle, we’ve created a chart that will make it a bit clearer. Think of your usual cycle length, AKA the number of days from the first day of your last period to the start of your next period (period tracking apps are a great way to get this info). Based on this number, refer to the chart to determine your best day to test. For example, if your cycle is usually 28 days and the first day of your last period started on the 7th, you should start testing on the 18th. In other words, if you have a 28 day cycle, you should start testing around day 10 or 11 to make sure you’re catching ovulation. If your cycle is irregular, use the midway point of your shortest cycle within the last 6 months and start testing there.
Like pregnancy tests, ovulation tests should be taken in the morning. Ovulation tests work by detecting a surge in the luteinizing hormone, LH, which has highest concentration levels in the morning before you drink any water. LH is important here as it helps control the menstrual cycle and triggers ovulation. This being said, sometimes it takes a few hours for ovulation tests to be able to detect LH, so taking another test later in the day if you suspect you might be ovulating is more than okay. This LH surge usually happens 12-36 hours before ovulation, so once your test is positive you should ovulate within that window. What’s most important is that you’re testing around the same time every day. The more you test, the more likely you are to accurately predict ovulation.
False Test Results
It’s important to note that ovulation test results show if your hormones are at the right level for ovulation. Ovulation tests are generally 97% accurate, but can be less reliable for women with irregular periods, health conditions like PCOS, or who are taking certain medications.
When we say “false results”, we are talking about instances in which the results of your ovulation test indicate that you are ovulating even though you aren’t, and vice versa. One possible cause of never getting a positive ovulation test result is from testing too early or too late. Figuring out when to test looks different for each person, depending on your cycle. Additionally, testing more frequently helps get in the know about what is happening in your body and what your cycle is like. We can’t stress this enough, but ovulation comes and goes in the blink of an eye, so you have to get to know your cycle a bit better in order to catch ovulation in your test results.
It can be hard to trust the results of your pregnancy and ovulation tests. We hear you. While inaccurate results are sometimes inevitable, we find that the more you know about when to test and how they work, the more confident you’ll be in the results your tests provide you. Stix does its best to avoid false results by providing simple instructions and clear results without evaporation lines.