No pregnancy sacs Why does the test paper have two bars

In the absence of a pregnancy sac, the strip test results showed two bars, probably because the time after conception is still relatively short, although the blood and urine chorionic gonadotropin showed a significant increase, but there is no pregnancy sac formed in the uterus. Second, the use of pregnancy test strips or pregnancy test method is not correct, the test results showed false positive. Third, it is indeed pregnant, and the number of days of pregnancy has exceeded 35 days, but the embryo development is abnormal, showing fetal arrest or biochemical pregnancy, so it will show bleeding in a short time. The specific reasons need to be analyzed according to the actual situation.