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Wondering if you can still get pregnant after a negative ovulation test? It may come as a surprise, but the answer is yes.
Ovulation predictor kits (OPKs) are a widely available tool to identify the fertile window during your cycle. A positive test identifies rising luteinizing hormone (LH) levels needed for your body to release an egg.
While OPKs may look like pregnancy tests, they’re not as straightforward. They require you to test at specific times during your cycle – and their results are not always clear-cut.
That’s because OPKs do not indicate ovulation. A positive test is only a predictor of the rise in LH levels.
Since LH levels and spikes vary among women, it may be challenging to capture your ovulation period with an OPK. A negative test may be a false negative.
This means you may still get pregnant even if you have a negative ovulation test.
So let’s learn a little more about ovulation and how OPKs work.
Pregnancy basics
How do you become pregnant? Your hormone levels change throughout your menstrual cycle to prepare your body for conception.
Before ovulation, your LH, estrogen, and follicle stimulating hormone (FSH) levels surge. These hormones prepare your ovary to release a mature egg during ovulation.
FSH rises at the beginning of your menstrual cycle to stimulate the follicles to grow. The mature follicles start releasing estrogen to build the uterine lining and prepare for pregnancy.
Once estrogen levels peak, your LH levels start rising to cause the rupture of the follicle. The ruptured follicle releases the egg.
After the egg is released, the ruptured follicle forms the corpus luteum. This structure produces progesterone. Progesterone nourishes the uterine lining, creating an ideal environment for the fertilized egg.
Once an egg is released, it only has a lifespan of 12-24 hours. However, sperm can survive for up to 5 days in the female reproductive tract.
If within 12-24 hours after ovulation, the released egg meets with a sperm, fertilization may occur.
If fertilization occurs, the zygote (fertilized egg) releases the human chorionic gonadotropin (hCG) hormone and your progesterone levels start rising.
If the egg didn’t get fertilized, your progesterone levels drop, resulting in your period.
How do OPKs work?
Traditional ovulation predictor kits (OPKs) detect LH levels in your urine. As ovulation approaches, there is a rapid spike in LH known as an LH surge. The hormone surge begins 36 hours before ovulation and peaks 10-12 hours before ovulation.
LH levels and surges are not one-size-fits-all. Some people have one LH spike, while others have two or three. Some even have plateau patterns where LH remains high for days.
As you can see, getting an accurate read on LH isn’t always easy. Add to that two subunits of LH – the alpha subunit and the beta subunit. The alpha subunit of LH is similar to that of three other hormones – hCG, FSH, and TSH (thyroid stimulating hormone).
This increases the chances of alpha LH cross-reacting with alpha hCG, alpha FSH, or alpha TSH. Most OPKs measure alpha LH and so, you may get false results based on this cross reaction.
Now that you know how OPKs work, let’s understand what is a negative result and how you may get it!
Negative ovulation test - What is it?
A negative ovulation test is when no test line appears on an OPK – only a control line.
A negative result on an OPK means that the test didn’t detect high enough levels of luteinizing hormone. This can mean one of four things:
- Ovulation will not occur in the next 10-12 hours
- The test was performed incorrectly
- The test was faulty
- The test was not sensitive enough to detect the LH surge
Let’s understand what could cause these negative results.
What causes a negative ovulation test?
There are several reasons you may get a negative ovulation test. Here are a few:
1 – Lower than average threshold
Most OPKs base their results on average thresholds. For example, many have a minimum threshold of 20-50 mIU/mL. If your LH falls above that number, you get a positive result.
But if your LH doesn’t cross that limit, you get a negative test result. Since LH levels vary widely among women and throughout your cycle, this could lead to a false negative.
You can avoid this by using an ovulation test that measures your actual hormone values, like Inito. Unlike threshold-based tests, Inito tracks your hormone trends throughout your cycle. This makes it less likely you’ll get a false negative.
2 – Anovulatory cycles
If your LH levels are too low to trigger ovulation, you’ll get a negative result on an OPK. This is known as an anovulatory cycle.
Anovulation is more common than you’d think. In fact, one study found that over a third of women experience anovulatory cycles. Many don’t even realize anovulation is an issue.
Progesterone is the key to confirming ovulation. After an egg is released, progesterone and its urine metabolite PdG start rising. That’s why Inito measures PdG, the urine metabolite of progesterone, to confirm ovulation occurred.
3 – Time of testing
OPKs differ from pregnancy tests. Pregnancy tests are best done with the first-morning urine (FMU) when the hCG hormone is highly concentrated.
LH also surges between midnight to 8:00 am and testing with FMU is the best way to do it for accurate results. However, many women take tests throughout the day which may skew the results.
And unlike pregnancy tests, ovulation tests are best done twice a day. This is because your results will vary depending on the type of LH surge you have:
- Short LH surge: Around 42% of women have short LH surges that are over within a day. If you have a short surge and only test once a day, you could miss it. This would result in a negative test.
- Double LH surge: Roughly 44% of women have biphasic surges, meaning one surge is followed by a second. If you only test once and have two surges, an OPK may not pick them both up. This could lead to a false negative.
4 – Faint lines
If you see a faint line on a test strip, it means LH was detected, but isn’t high enough to suggest a surge. Faint lines do not equal a positive test result on an OPK.
If this happens on an analog test, your test will show a control line and a faint test line. If it’s a digital test, you’d get a negative result.
Read More: What does a faint line on an ovulation test mean?
5 – Manual errors
Sometimes a negative result is due to a user error or a faulty test. Here are a few ways that can happen:
- Dipping error: If you dip the test strip in your urine for too long or not long enough, it can skew your results. So be sure to follow the instructions to the tee.
- Reader error: Interpreting analog tests can be confusing. For a positive result, the test line must appear as dark or darker than the control line. This leaves a lot of room for interpretation.
- Faulty strip: Sometimes, a test is just defective. Before testing, always be sure to check the date to make sure it hasn’t expired.
Now that you have understood the causes of a negative result on an OPK, read on to find out if you can get pregnant with a negative ovulation test.
Can I still ovulate with a negative ovulation test?
OPKs are a predictor of ovulation. Given that all women’s cycles are different, the OPK may not capture your LH surge. You can still ovulate even with a negative ovulation test!
How can you get pregnant with a negative ovulation test?
You can still become pregnant even with a negative ovulation test! How can that happen?
As mentioned, most OPKs base their results on average thresholds. If your LH is lower than average, you could get a negative test result even if you ovulated.
One study measured the LH surges of 40 women. It found that LH surges can be as low as 6.5 mIU/mL, and still trigger ovulation. Some sensitive OPKs detect LH levels as low as 22 mIU/mL.
So what does this mean? If your LH levels fall under 22 mIU/mL, your surge won’t trigger a positive test.
Since you did ovulate, your egg is ready to meet the sperm and get fertilized. The fertilization may result in a positive pregnancy.
Will ovulation tests be negative if pregnant?
LH levels drop just prior to ovulation. So it’s likely that you would have a negative OPK if you are pregnant.
Your beta hCG levels start rising when you get pregnant. Since most ovulation tests measure your alpha LH levels, this can cross react with the beta hCG in your body. The cross reaction gives rise to a false positive result on the ovulation test.
Summing it up:
Ovulation predictor kits can be extremely useful in predicting ovulation. However, it would help if you understood precisely what the OPK result means. A positive result from an OPK that only measures LH, indicates that your LH levels are surging. This surge suggests that ovulation may occur in the next 24 hours.
However, OPKs utilize one specific pattern of LH, and we’ve seen that the majority of women of childbearing age have varied LH patterns. This means there’s a lot of variability around ovulation and that you can still get pregnant after a negative test.
Key Points about OPKs:
- Ovulation predictor kits measure surges of LH before ovulation. But, they do not indicate whether ovulation will occur.
- There are many reasons why you may have a negative OPK, including miscalculating or mispredicting your cycle length or using tracking methods that multiple factors may influence.
- OPKs are best performed in the afternoon when LH typically peaks.
- OPKs use the textbook model of one singular peak of LH prior to ovulation. Data shows that most women have LH patterns that vary from this model.
- Reading the results of analog OPKs can be confusing as you need to compare the depth of color of the test line to the control line.
- A positive OPK does not ensure ovulation will occur.
- Use the Inito Fertility Monitor to track your fertile window and confirm ovulation accurately.
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- The Normal Menstrual Cycle and the Control of Ovulation – Endotext – NCBI Bookshelf
- Menstrual Cycle – an overview | ScienceDirect Topics
- Basal body temperature assessment: is it useful to couples seeking pregnancy?
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- Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation? – PMC
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