The accuracy rate of pregnancy test stick is 90%-95%, therefore, there are cases of inaccurate results, and the operation method, testing time and changes in personal hormone level can affect the test results of pregnancy test stick. 1. Operation method: the operation should be strictly in accordance with the instructions of pregnancy test stick, if the operation is incorrect, the test results may be inaccurate. 2. Therefore, if the test is conducted too early, accurate results may not be obtained. 3. Hormone level: Since the pregnancy test is determined by the level of human chorionic gonadotropin in urine, it is best to choose the urine after waking up in the morning to conduct the test, as the concentration of this hormone in the morning urine is the highest and the test results are more accurate accordingly. In addition, if the patient drinks a lot of water before the test, the hormone concentration in the urine may drop, which may lead to false negative test results. 4. Observation time: Usually the observation time of the pregnancy test stick is within 1-5 minutes after the test, if the observation time is lower or beyond this range, there may be errors. In addition, the poor quality of the pregnancy test stick and its expiration date and deterioration can also lead to inaccurate test results. If you suspect an early pregnancy, you should go to the hospital to have a blood test for human chorionic gonadotropin level and a follow-up ultrasound to confirm the diagnosis, regardless of the pregnancy test result.