Generally 7-10 days after coitus can draw blood HCG, coitus half a month early pregnancy test paper can detect pregnancy. Under normal circumstances, the fertilized egg is deposited in the endometrium on the 6th day, and the cell trophoblast formation starts to secrete trace amounts of HCG, which can be detected in the mother’s blood on the 7th day after fertilization. Within 1 week after implantation of the fertilized egg, the serum HCG level rises from 5 IU/L to 50 IU/L. 14 days after implantation, it is about 100 IU/L. Therefore, you can take a blood sample of HCG 7-10 days after intercourse to test whether you are pregnant or not. Early pregnancy test is to know whether you are pregnant or not through the urine HCG value, which is relatively later than blood HCG, and can be detected half a month after the coitus. If you find that your period exceeds the usual date, you can use the pregnancy test stick to test yourself, the accuracy is still very high, and it is easier to test yourself at home, you will be able to know whether you are pregnant or not in a few minutes. If urine HCG is positive, further blood HCG and ultrasound are needed to determine the development of the embryo.