A blood test is the most accurate way to determine a patient’s pregnancy, while a urine test is more accurate but less accurate than a blood test. The blood HCG test is more accurate than the urine test in determining whether a patient is pregnant, and it can also determine pregnancy earlier than the urine test, with the blood test detecting pregnancy 3-5 days earlier than the urine test. The blood HCG test can not only determine whether the patient is pregnant or not, but also the activity of the patient’s gestational sac, which can help determine whether the patient has a preterm miscarriage and whether there is a possibility of ectopic pregnancy, and is a good guide for patients who have a history of miscarriage to preserve the pregnancy. However, the blood test is an invasive test. If there are no special circumstances after the pregnancy, the patient can determine whether she is pregnant through urine, and the accuracy rate of urine test is also relatively high, at about 99%.