This test is undertaken in order to find out whether a woman is pregnant or not. These tests are undertaken in order to find for the presence of the beta submit of hCG or human chorionic gonadotropin in urine or blood. These tests are usually performed after a missed menstruation or about two to three weeks after ovulation.
hCG is released by trophoblastic tissue in the placenta. Quantitative serum beta hCG levels are also performed by doctor. If the level is above 25mIU/ml it indicates that pregnancy has occurred. Two tests are required to be done in order to verify a normal increase which is generally two to three days apart.
Once pregnancy has been advanced past the first six to eight weeks, pregnancy can be easily followed by sonography as more information can be produced in real time. Pregnancy can be detected twenty five days after ovulation by transvaginal sonography. Negative readings might occur when the concentration of the hCG in the woman’s urine falls below the threshold level of the detection by the test. It can happen before the fifth week of pregnancy. A blood test can detect the hCG level by about ten to eleven days after ovulation.