There are several ways to determine if you are pregnant: First, to determine if you are pregnant at the earliest, you can go to the hospital eight to nine days after intercourse and have a blood test for progesterone, if the progesterone value is above ten, you can be sure that you are pregnant. Secondly, you can also infer whether you are pregnant according to the delayed menstruation. It is possible that you are pregnant if your menstruation is delayed for more than a week, but some gynecological diseases may also cause delayed menstruation, so the delayed menstruation cannot be very accurate to infer whether you are pregnant. Thirdly, on the fifteenth day after intercourse, you can use early pregnancy test paper to detect whether you are pregnant or not. Fourth, pregnancy can be inferred from the vomiting reaction after pregnancy, which occurs one month after the cessation of menstruation. Fourth, you can use early pregnancy test paper. These are the methods and clinical symptoms used to detect pregnancy. If you have any of the above signs, you can go to the hospital for HCG or gynecological ultrasound for further confirmation.