Taking an Ovulation Test when Pregnant: Will the LH Surge Stay High?

 

If you are trying to conceive, you probably find a lot of information and get advice on products promising to help you get pregnant. It can feel overwhelming, particularly when conceiving takes longer than expected. 

The American College of Obstetrics and Gynecology states that to get pregnant, you must know when ovulation happens and plan accordingly. Knowing your most fertile days takes some math and understanding your menstrual cycle. For instance, if your cycle is between 26 and 28 days long, then ovulation happens between days 12 and 14 in any given cycle. 

If you’re unsure of when you’re ovulating, a pelvic ultrasound in the clinic is one of the best for ovulation detection in hospitals. But one solution you can do at home that is 99% accurate is an ovulation test. The test finds if there is a rise in luteinizing hormone (LH). A surge in this hormone signals the ovary to release the egg. However, it can rarely give a wrong result. 

In a few instances, an ovulation test can give a false positive, which looks like a second test line and the control line. When doctors do further tests, some women find out that the false positive result was due to pregnancy. 

In this article, we’ll explore what happens to your hormones when you’re pregnant and the difference between ovulation and pregnancy tests. 

Will an Ovulation Test Be Positive If You’re Pregnant? 

No, an ovulation test will not be positive if you’re pregnant since it was not designed to detect pregnancy. But on rare occasions, it might show a false positive result.

Ovulation test strips and pregnancy tests measure different hormones. Ovulation tests detect LH, which spikes just before ovulation. Pregnancy tests detect human chorionic gonadotropin (hCG), which rises rapidly during early pregnancy.

Although LH and hCG share a similar structure, they’re different hormones. This similarity can sometimes lead to cross-reactivity, meaning an ovulation test might mistakenly detect hCG as LH. However, this is generally only a concern during the early stages of pregnancy. As hCG levels rise significantly during pregnancy, the chances of an ovulation test detecting it decrease.

Understanding Ovulation Tests

Many methods to detect ovulation are available, including the basal body temperature, calendar, and cervical mucus methods. However, these are limited to the body’s physical signs and can be influenced by other factors. Compared to these methods, ovulation test kits or ovulation predictor kits (OPKs) are a cheap but not very accurate test for LH as they work with standard thresholds, whereas hormone monitoring such as the Mira Max Kit is much more reliable.

How Do They Work?

Ovulation tests detect the amount of LH in your pee. A high concentration of LH in urine means that you are about to ovulate, usually in the next 24-36 hours. If you get a positive result, it is the best time to have sex if you’re trying to get pregnant. However, if you have a negative result, you can keep testing before the estimated ovulation day based on your cycle and check urinary LH once or twice daily.

When using the ovulation test kit, you either pee directly on the absorbent tip of the stick or dip the test stick into a cup of collected urine. Depending on the product instructions, the testing process usually requires keeping the absorbent part in the urine for a specified duration.

After a short waiting period, the results appear, typically as lines, symbols, or numbers, which indicate whether the test is positive (indicating a surge in LH and the likelihood of ovulation) or negative.

Using the Mira hormone tester is quite easy. You dip the test wand into urine for 10-20 seconds.

Then insert the wand into the Mira Hormone Monitor. Your hormone results will automatically sync with the Mira App in 21 minutes. The analyzer device then evaluates hormone levels in the urine and sends its findings to the Mira App. The analyzer device also works with artificial intelligence to track hormone patterns.

What Do They Test?

Ovulation tests primarily test for testing levels of LH. This is the main hormone detected by ovulation tests. A rise in LH levels indicates an ovulation event is about to occur, usually within the next day or so. Ovulation tests effectively identify the fertile window by measuring hormone levels in urine. They help increase the chances of conception for people trying to get pregnant.

When Should You Take One? 

Generally, the testing should begin between days 10 and 13 of your menstrual cycle or fertile window. For this timing, they use the 28-day cycle. However, if the cycles are not of average length and are infrequent or even shorter than normal, you may need to adjust the testing schedule.

Here’s a breakdown of how to determine your testing window:

• Monitor your menstrual cycle: The best way to calculate your usual cycle length is to note the time it takes for one cycle carefully.
• Calculate your fertile window: Subtract 18 from your shortest cycle length. The resulting number is approximately when your fertile window starts For example, If your shortest cycle length is 30 days, you would subtract 18 from 30 to get 12. That is when your fertile window starts and when you can start testing.
• Start testing: Begin testing a few days before your calculated fertile window. Since ovulation timing can fluctuate from cycle to cycle, taking multiple tests over a few days is often recommended to increase the likelihood of capturing the LH surge.

LH Surges and Pregnancy

LH surges play a crucial role in the menstrual cycle, particularly in triggering ovulation, which is essential for conception. An egg is released from the ovary approximately 24 to 36 hours after a significant rise in LH levels. 

For those trying to conceive, detecting this surge through ovulation tests can help timed intercourse for couples trying to conceive and give them the highest chance of a pregnancy. After ovulation is complete, continuing testing for LH during your current cycle is no longer necessary.

What Are My LH Levels If I’m Not Pregnant?

LH (luteinizing hormone) levels fluctuate throughout the menstrual cycle, with specific ranges considered normal. Here’s a summary of LH levels at various points:

Baseline Levels

• Follicular Phase: Typically between 1.9 to 14.6 IU/L.
• Luteal Phase: Typically between 0.7 to 12.9 IU/L.

Lowest Levels

• LH levels are lowest during the luteal phase (0.7 to 12.9 IU/L) in women with a regular cycle.

Highest Levels

• LH surges 24-36 hours before ovulation, ranging from 12.2 to 118.0 IU/L.
• In menopausal women, LH levels range from 5.3 to 65.4 IU/L.

What Are My LH Levels If I’m Pregnant? 

LH levels can drop significantly in pregnant women, often below 1.5 IU/L, after the placenta takes over the hormones necessary to sustain pregnancy.  

In contrast, hCG levels rise rapidly after implantation. This hormone is what pregnancy tests detect. So, using an ovulation test to detect pregnancy can be unreliable. While a false positive ovulation test can be possible due to high hCG levels, it’s not a reliable method for confirming pregnancy.

What If You’re Pregnant?

Pregnancy Test vs Ovulation Test 

Pregnancy tests and ovulation tests are two essential fertility testing tools for women seeking to understand their reproductive health. While they both involve testing for hormones, they serve different purposes. 

Feature	Pregnancy Test	Ovulation Test
Purpose	Detects hCG to confirm pregnancy	Detects LH to predict ovulation
Hormone Detected	Human Chorionic Gonadotropin (hCG)	Luteinizing Hormone (LH)
Timing	Typically taken after a missed period	Taken a few days before expected ovulation
Positive Result	Indicates pregnancy	Indicates a potential surge in fertility
Negative Result	It may indicate no pregnancy, but early testing can sometimes give false negatives	It may indicate that ovulation hasn’t occurred yet
Accuracy	Generally highly accurate, especially when taken after a missed period	It can be affected by factors like irregular ovulation or medication use

Should You Use an Ovulation Test as a Pregnancy Test?  

No, you should not use an ovulation test as a pregnancy test. While both tests measure hormones, they are designed for different purposes.

Ovulation tests are designed to detect luteinizing hormone (LH), which surges just before ovulation. They are not as sensitive to human chorionic gonadotropin (hCG), which rises rapidly during pregnancy.

Using an ovulation test as a pregnancy test can lead to inaccurate results. A false negative may occur if the hCG levels are too low to be detected by the ovulation test. Conversely, a false positive may occur if the ovulation test mistakenly detects hCG as LH.

What Test Should You Use to Check for Pregnancy? 

It is advisable to opt for a pregnancy test tailored to detect hCG. These tests are created to recognize hCG and give precise results. Here are a few choices and factors to think about:

• Home pregnancy tests are easily accessible and can be utilized a few days before your expected period. Their usual sensitivity is approximately 10-25 mIU/mL of hCG. Always follow the specific instructions provided with your ovulation test kit.
• Pregnancy tests that provide early results have higher sensitivity and can identify hCG levels as low as 10 mIU/mL. They are perfect for individuals with unpredictable cycles or for detecting pregnancy early.
• Pregnancy tests done with blood: They are performed at a medical facility and can identify hCG levels as low as one mIU/mL. They are the most delicate choice and can deliver outcomes in just a few hours.

Typically, the ideal moment to do a pregnancy test is after you have not had your period as expected. Early detection tests can potentially identify pregnancy before this period. Doctors will advise you to wait a few days after the anticipated ovulation date to do a pregnancy test if you have irregular cycles.

Frequently Asked Questions