A pale second line may appear on the test in the case of a so-called "chemical pregnancy". This name is used to identify pregnancies that terminate before four weeks - most women do not know that they are having a miscarriage and mistake it for normal periods. Doctors say that approximately 70 percent of all pregnancies are chemical and end without the woman's knowledge. However, pregnancy is pregnancy, which means that the level of hCG can change (increase until the moment of miscarriage and gradually decrease after it).