Early pregnancy test paper can not detect pregnancy and menstruation did not come because the pregnancy test time is relatively early, menstrual disorders, urine is diluted and so on. 1. early pregnancy test: if the pregnancy test time is relatively early, the HCG concentration in the urine has not yet reached a certain level, the test will appear negative results, you can after a week to test again. 2. Menstrual disorders: If there is a delay in menstruation, the early pregnancy test paper will also show negative results, which may be due to endocrine disorders, recent mental stress, late night and other reasons, you can wait a few days to see if the menstrual period. 3. Diluted urine: Drinking a lot of water before taking the urine specimen will cause the urine to be diluted, and a negative result may never occur. You can wait for two days before taking the test again, or you can go to the hospital.