Pregnancy refers to the physiological process from conception to delivery, and generally before 12 weeks of pregnancy we call it early pregnancy, which is usually referred to as early pregnancy. There are many methods to detect early pregnancy, and the time period of detection is different, and the methods of detection are also different. The most common detection methods we usually use are early pregnancy test paper test, basal body temperature test, ultrasound test, and blood HCG test. 1.Early pregnancy test paper test: Generally, the test is started 3 to 5 days after the menstruation is postponed. Drink less water at night to avoid dilution of urine, and the test is more accurate the next morning with morning urine, if the test result is two red lines, it means positive and the possibility of pregnancy is higher. 2.Basal body temperature detection: It means that the normal female body temperature before ovulation is usually below 36.5 degrees, and after ovulation the body temperature rises 0.3-0.5 degrees than before. If the body temperature after ovulation has been maintained at an elevated level for more than 18 days without falling, pregnancy is highly suspected. 3.B ultrasound: After the sperm and egg unite to form a fertilized egg, the cells will keep dividing and proliferating and move to the uterine cavity for planting, and it takes some time for the embryo to develop to a large enough size to be detected by ultrasound, so ultrasound testing is best done after a week of delayed menstruation for more accurate results. 4.Blood HCG test: It is more sensitive, usually HCG secretion starts 7 days after fertilization, and can be detected in blood in 10 days, so blood can be drawn to check whether pregnancy. Blood HCG test does not require fasting. Therefore, the time to detect early pregnancy depends mainly on the early pregnancy test you choose. If you have sex without contraception and your period is delayed, you can follow the above-mentioned methods to confirm whether you are pregnant at the corresponding time.