Ovulation test paper has only one line. What's going on?

Ovulation test results are influenced by a number of factors. Water intake should be reduced two hours before urine collection, as diluted urine samples can interfere with detection of peak LH. In addition, please note that before use, do not let the test strip get wet or touch the reaction film. After taking out the canned test strip, please immediately cover the jar tightly. The test strip should be used within the expiration date. Do not use it after the expiration date. Do not take hormone drugs or eat fried foods to prevent affecting the test results.