It is difficult to know clinically how many days pregnant you are by the presence of two red bars of the same color on the early pregnancy test, because it is possible to see two bars after about 35 days of pregnancy, as the concentration of HCG in the urine increases. In addition, in the case of ectopic pregnancy, two red bars of the same color may appear as time passes. In the case of staph, it may also result in two red bars. Therefore, the final clinical diagnosis of how many days pregnant and whether it is an intrauterine pregnancy or an ectopic pregnancy or a gravida needs to be confirmed by ultrasound, which is used to measure the size of the gestational sac in order to know how long the pregnancy has been, and also to give a comprehensive analysis in conjunction with the time of the last menstrual period.