Ovulation tests and pregnancy tests: They both involve peeing on a stick, but they measure completely different things. Ovulation tests look for a surge in luteinizing hormone (LH), which tells you that you’re about to ovulate. Pregnancy tests detect human chorionic gonadotropin (hCG), which confirms that you’re pregnant.
So, can an ovulation test detect pregnancy? The short answer is: sort of. While ovulation tests aren’t designed to detect pregnancy, they can sometimes show a positive result if you’re pregnant. That’s because of the similarities between LH and hCG.
We’ll break down the differences between ovulation and pregnancy tests, why an ovulation test might show a positive result when you’re pregnant, and the best ways to confirm whether you’re expecting.
How Ovulation Tests Work
Ovulation tests are designed to detect the surge in luteinizing hormone (LH) that happens right before ovulation. That LH surge is what triggers the release of an egg from your ovary, usually about 24 to 48 hours after the test detects that your LH is elevated.
You can buy ovulation tests at most drugstores and pharmacies.
Detecting the LH Surge
The most common type of ovulation test involves peeing on a stick or dipping a test stick into a cup of urine. Digital ovulation tests have a screen that will show you a “yes” or “no” type of result.
Timing is Key
If you have a typical 28-day cycle, you’ll want to start testing a few days before you expect to ovulate, around day 10 to 13 of your cycle. There are period tracker apps that can help you predict your fertile window.
Some experts recommend testing first thing in the morning, when your urine is the most concentrated. Others say that LH surges tend to occur in the morning, so testing between noon and 8 p.m. might be best.
How Pregnancy Tests Work
Pregnancy tests work by detecting human chorionic gonadotropin (hCG) in your urine or blood. After a fertilized egg implants in your uterus, the developing placenta starts to make hCG. The amount of hCG in your system doubles every few days, and a pregnancy test will be able to detect it about two weeks after conception.
Home pregnancy tests are easy to find and pretty accurate if you use them correctly. Some early detection tests are extra sensitive and can pick up lower levels of hCG. Blood tests are the most accurate, but you’ll need to see a healthcare provider to get one.
For the most accurate result, wait until after you’ve missed your period to take a pregnancy test. If you’re using an early detection test, you can try it a few days before your period is due.
LH and hCG: Understanding the Hormonal Connection
To understand why an ovulation test might show positive when you’re pregnant, it helps to know a bit about the hormones involved.
Similar Structures, Different Roles
Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) are two hormones that, despite having different jobs, have similar molecular structures. Because of this similarity, some tests can get them mixed up.
LH is the hormone that triggers ovulation — the release of a mature egg from the ovary. LH levels surge around the middle of your menstrual cycle, signaling that it’s time for ovulation to occur.
hCG, on the other hand, is a hormone produced during pregnancy. It supports the corpus luteum, which produces progesterone, a hormone essential for maintaining the uterine lining during early pregnancy. hCG levels rise rapidly in early pregnancy.
Why Ovulation Tests Might Detect Pregnancy
Because LH and hCG share similar structures, an ovulation test might detect hCG, especially in early pregnancy when hCG levels are high. In this case, the test is “erroneously detecting the high hCG levels of a pregnancy and not LH.”
However, ovulation tests aren’t designed to detect pregnancy. So, while it can happen, it’s not a reliable indicator. If you suspect you’re pregnant, it’s always best to take a pregnancy test for an accurate result.
Interpreting Test Results: Ovulation vs. Pregnancy
If you’re using ovulation tests to track your cycle, it’s important to know what the results mean in combination with other factors, like whether you’ve taken a pregnancy test and whether you’ve missed your period.
- Positive Ovulation Test, Negative Pregnancy Test: This likely means that you’re experiencing an LH surge and ovulation is probably about to happen. Now’s the time to have intercourse if you’re trying to get pregnant.
- Positive Ovulation Test, Positive Pregnancy Test: This could mean you had an LH surge earlier in your cycle and you’re pregnant. It’s a good idea to confirm the pregnancy with your doctor.
- Positive Ovulation Test, Late Period: A positive ovulation test and a late period strongly suggest that you could be pregnant. Take a pregnancy test right away to find out for sure.
- Negative Ovulation Test, Negative Pregnancy Test: This result means that you’re not pregnant and you’re not currently ovulating. Keep tracking your cycle and testing to pinpoint when ovulation occurs.
While ovulation tests can sometimes detect pregnancy, they’re really designed to detect an LH surge. If you think you might be pregnant, it’s best to take a pregnancy test and see your doctor for confirmation.
Sorting out ovulation symptoms from early pregnancy symptoms
It can be tricky to tell whether what you’re feeling is an indication of ovulation or an early sign of pregnancy because many of the symptoms are the same. Both can bring on breast tenderness, fatigue, mood swings, and a higher basal body temperature.
Here are some of the telltale signs of ovulation:
- More cervical mucus, which will be clear, slippery, and stretchy
- Mittelschmerz, or mild cramping or pain in the lower abdomen
- Increased libido
Here are some of the early signs of pregnancy:
- Missed period
- Implantation bleeding, which is light spotting caused by the fertilized egg implanting in the uterus
- Nausea and vomiting (morning sickness)
- Frequent urination
- Fatigue
Because the symptoms can be so similar, it’s important to confirm a possible pregnancy with a pregnancy test. Don’t rely on symptoms alone to determine whether you’re pregnant or not.
When to see a doctor
If any of the following apply to you, you may want to consult a healthcare professional:
- Irregular periods: Irregular periods can point to conditions like polycystic ovary syndrome (PCOS), which can impact fertility.
- Difficulty conceiving: If you’ve been trying to get pregnant for several months without success, it’s time to seek medical advice.
- Worries about test results: If you’re unsure about your ovulation or pregnancy test results, your doctor can help.
- Recurrent pregnancy loss: Recurrent miscarriages may indicate an underlying issue that your doctor can help you identify and address.
Closing Thoughts
Let’s be clear: Though an ovulation test might show a positive result in early pregnancy, it’s not designed for that purpose and shouldn’t be relied upon as a pregnancy indicator. While it’s understandable to grasp at any potential sign, you need to use the right tool for the job.
If you suspect you’re pregnant, take a pregnancy test. That’s what they’re for! And if you’re trying to conceive, tracking your menstrual cycle and ovulation is crucial for maximizing your chances.
Finally, and most importantly, if you have any questions or concerns about your reproductive health, please consult with a healthcare professional. They can provide accurate information and personalized guidance to help you on your journey.