The diagnostic accuracy of pregnancy test sticks is relatively high, but there are still certain errors, and the test results can be affected by many factors. For example, some women may see two lines on the pregnancy test stick during testing but are not pregnant. This situation can occur, and the reasons for this result are relatively complex, requiring consideration of multiple factors. So what causes a pregnancy test stick to show two lines but no pregnancy?

1. False Positive Appearance

When a pregnancy test stick shows two lines but there is no pregnancy, the first consideration is that the quality of the test stick itself is abnormal, leading to a false positive appearance. Again, since the pregnancy test stick detects the hCG hormone in urine, but there is no pregnancy, then it is necessary to consider diseases such as gestational trophoblastic neoplasia that can cause an increase in hCG levels in the blood and urine, leading to two lines on the pregnancy test stick. Therefore, it is necessary to check blood hCG levels and perform ultrasonography to confirm trophoblastic neoplasia.

2. Expired Test Strip

When a pregnancy test stick shows two lines but there is no pregnancy, this situation may be caused by the quality of the test strip or the expiration of the test strip. If the test strip has expired or is past its shelf life, there may be approximately 30% error. Therefore, there is a certain margin of error when using pregnancy test sticks or test strips to detect pregnancy. If the test shows two lines but ultrasonography at the hospital does not detect pregnancy, it does not necessarily mean that there is no pregnancy. It may also be that the pregnancy is relatively short and temporarily undetectable. In such cases, it is recommended to wait for a week and then go to the hospital for a follow-up ultrasonography.

3. Precautions

The results of pregnancy test sticks can only be used as a reference, as there are many factors that can affect the test results. Therefore, for further confirmation, it is best to undergo medical examination. The results of self-testing with pregnancy test sticks can only be used as a reference. There are many factors that can affect the results of pregnancy test sticks. For example, within 7 days after sexual intercourse during the ovulation period, when the hCG hormone level in the body is relatively low, it is easy to obtain a false negative result with a pregnancy test stick. Additionally, if the menstrual period is delayed for more than 7 days and the pregnancy test stick shows a negative result, it should not be taken lightly as there may be issues with certain aspects. If a blood test is performed at the hospital at this time, the result may also be positive.