A pregnancy test a deep and light blood draw does not necessarily detect pregnancy, because a positive pregnancy test may be physiological HCG elevation, there may be a pathologic HCG elevation, there may be improper use. 1. Physiological HCG elevation: luteinizing hormone peaks before ovulation, luteinizing hormone and HCG have the same subunit, so there will be a pregnancy test a deep and a shallow situation. 2. Pathological HCG elevation: some ovarian tumors, such as yolk cystic tumor and other tumors that can secrete HCG, as well as severe hypothyroidism in the body of more thyrotropin can make the pregnancy test stick show false-positive results. 3. Improper use of pregnancy test: the correct way to use pregnancy test is to read the results after adding the sample for 3-5 minutes, after more than 5 minutes, there may be no pregnancy and false positive results. It is recommended that women of childbearing age who have a positive pregnancy test can seek medical attention to do the relevant examinations, if the pregnancy should be on time after the obstetric examination, if there is no pregnancy should be ruled out the above kinds of false-positive situation, and timely treatment of the original disease.