If the test paper is positive and the blood test is not pregnant, it may be caused by a false positive test paper test, which is mainly related to the expiration of the early pregnancy test paper, incorrect testing methods and other reasons. The test paper is not 100% accurate, so you need to rely on blood tests and abdominal ultrasound to accurately determine pregnancy. 1. Expired early pregnancy test paper: when using early pregnancy test paper, if the test paper is expired, it is usually not accurate to determine pregnancy, and false positives may occur; 2. Incorrect detection method: early pregnancy test paper is a common way to determine early pregnancy, mainly to detect human chorionic gonadotropin in urine. However, it is easily affected by external factors during the detection, and false positives may occur if the detection method is not correct. The test is susceptible to external factors and may result in false positives if the test is not performed correctly, such as prolonged urine retention or contamination of the test strip. The test results are not completely accurate and further blood tests are needed to check the human chorionic gonadotropin in the blood. If the value is high, it usually indicates pregnancy. Alternatively, an abdominal ultrasound can be done 1 week after the menstrual period is delayed to check for the presence of a gestational sac in the uterus, as these tests are more accurate.