How many days without a period can you test for pregnancy

If a woman has regular menstruation and her period comes once every 28 days, she can use pregnancy test paper to detect pregnancy after 40 days of menopause, and she can draw blood to detect pregnancy after 10 days of coitus.
Women who have regular menstruation, take 28 days as the menstrual cycle as an example, and have normal sex, if they do not have menstruation for about 40 days, they can use the pregnancy test paper to detect whether they are pregnant or not. If a woman is pregnant at this time, the level of human chorionic gonadotropin in the urine begins to rise, generally can be detected through the early pregnancy test paper.
Women who have normal sex life and normal physiological function, if you want to know pregnancy earlier, you can go to the hospital 10 days after intercourse to draw blood to test human chorionic gonadotropin.
If a woman is initially sure that she is pregnant, she should also go to the hospital in time for further examination of the uterine adnexa ultrasound to determine whether the embryo is growing in the uterus, and should consult the doctor in time if there is abdominal pain and vaginal bleeding.