Ovulation tests, known as Luteinizing Hormone (LH) tests, detect a significant spike in the pituitary hormone LH. This spike, or surge, serves as the final signal that triggers ovulation. Since the surge is typically a brief event, a continuous stream of positive results is confusing. Persistent positivity usually stems from testing errors, natural hormonal variability, or an underlying medical condition affecting hormone regulation.
Understanding the Test Threshold
Ovulation test strips measure the concentration of LH in a urine sample against a preset chemical threshold. Most over-the-counter tests are qualitative, indicating only if the LH level has crossed a specific value, typically 25 to 30 mIU/mL. A result is considered a true positive only when the test line is as dark as, or darker than, the control line, confirming a surge. A faint test line is a negative result reflecting the body’s low, baseline level of LH.
Test strip brands vary in sensitivity; a less sensitive test might turn positive at 30 mIU/mL, while a highly sensitive one might trigger at 20 mIU/mL. Individuals with a naturally higher baseline LH level may find their normal concentration approaches or crosses the threshold of a sensitive test. This results in days of dark lines that indicate a personal high baseline, not a true surge.
Errors in Testing Protocol
Errors in testing timing or technique are frequent reasons for continuous positive readings. Testing too early, or failing to stop after the first true positive, can unnecessarily extend the apparent positive period. Although the LH surge is rapid, testing multiple times a day is recommended to catch the peak. This frequency can also capture the entire duration of the surge, which may last several days in some individuals.
Urine concentration significantly influences the test result, potentially causing a false positive or prolonging a dark line. Testing with highly concentrated urine, like first morning urine, is discouraged because accumulated hormone levels may not reflect the current surge status. Conversely, excessive fluid intake before testing dilutes the urine, making a true surge appear lighter or negative. This dilution can lead to over-testing and misinterpretation.
A simple but common error is misreading a dark shadow or faded line as positive. Only count the result as positive when the test line is undeniably equal to or darker than the control line.
Normal Physiological Variations
The duration and pattern of the LH surge vary naturally among individuals, easily leading to multiple positive tests in a row. Some women experience a protracted surge lasting 48 to 72 hours, correctly registering a positive result for two or three consecutive days. This extended period of high LH is a normal physiological occurrence and precedes ovulation within the expected timeframe.
Another normal variation is the occurrence of multiple or “failed” surges within the same cycle. In this scenario, the body releases LH, attempting to ovulate, but the egg is not successfully released. This causes a positive test followed by a return to negative results. The body may then attempt another surge shortly after, leading to a second sequence of positive tests later in the cycle. Additionally, some individuals exhibit a gradual-onset LH pattern, where the hormone level slowly climbs over several days before peaking, resulting in multiple days of positive or near-positive results.
Underlying Medical Explanations
If ovulation tests consistently remain positive across many days or weeks, an underlying medical condition may be affecting hormonal balance. The most common explanation is Polycystic Ovary Syndrome (PCOS), characterized by chronically elevated baseline LH levels. Since the hormone concentration is already high, the test strip’s threshold is continuously met, leading to persistent positive results that do not accurately predict ovulation.
Hormonal states or medications can interfere with the test’s ability to distinguish a true surge. Human chorionic gonadotropin (hCG), the hormone detected by pregnancy tests, shares a structural similarity with LH. Its presence in early pregnancy can cause a false positive ovulation test. Similarly, certain fertility medications, especially those containing LH or hCG, directly impact results.
Conditions like perimenopause or primary ovarian insufficiency can also cause LH levels to become erratic or chronically elevated as the body attempts to stimulate the ovaries. If positive results are consistently received over multiple cycles, consult a healthcare provider to rule out these medical explanations.