A negative HCG result means that it is unlikely that a woman is pregnant.
However, tests performed too early in a pregnancy, before there is a significant HCG level, may give false-negative results. The test may be repeated a few days later if there is a strong possibility of pregnancy.
A positive HCG means that a woman is likely pregnant.
Typically, HCG levels double about every two days for the first four weeks of a normal pregnancy, then slow to every 31/2 days by six weeks.
Those with failing pregnancies will also frequently have a longer doubling time early on or may even show falling HCG concentrations during the doubling period. HCG concentrations will drop rapidly following a miscarriage.
In men and in non-pregnant women, the HCG level is normally undetectable. When the test is used as a tumor marker, an elevated HCG level may mean that an individual has a germ cell tumor.