Level 1: How early in pregnancy can a preliminary test be done? Pregnancy is something that every woman looks forward to, but before we start looking forward to it, we need to know how long into the pregnancy we can take a preliminary test. Generally speaking, women can take preliminary tests about 7-10 days after conception. At this time, the level of human chorionic villi (HCG) in a woman’s body begins to increase, which is also the most sensitive period in early pregnancy. Preliminary testing usually uses urine test strips or blood tests. Urine test strips are more convenient and can be used at home