20 days after intercourse with the test paper is more accurate, but the accuracy of the test paper is also affected by other factors, such as the test paper after the expiration date, the use of incorrect methods will reduce the accuracy. Generally in 14 days after intercourse, you can use the pregnancy test paper to carry out the pregnancy test, has been 20 days after intercourse, the concentration of human chorionic gonadotropin in the urine is relatively high, is generally able to test out the woman is not pregnant. The correct test method can increase the accuracy of the test paper, at first try to choose the morning urine to go to the pregnancy test, morning urine in the human chorionic gonadotropin concentration is relatively high, before the test first check the test paper is within the validity period, there is no damage or contamination of the situation, there is no problem and then use the correct method to go to the pregnancy test. A negative test result means that you are not pregnant, a weak positive test result requires you to retest in a few days, and a positive test accompanied by menopause basically means that you are pregnant. In clinical practice, it is recommended that women go to the hospital to test for pregnancy, as the accuracy rate will be higher.