You can start a pregnancy test before your period is delayed for about 5 days or even before there is no delay in your period. The process of fertilized egg formation is that the ovary ovulates and picks up the egg via the fallopian tube umbrella, which transports the egg to the fallopian tube to meet and combine with sperm to form a fertilized egg. After about 6 days the fertilized egg arrives in the uterine cavity to settle and then develop, after which the endometrium stops thickening and menstruation stops. After a woman becomes pregnant, the levels of estrogen, progesterone and human chorionic gonadotropin in her body increase significantly. Therefore, a pregnancy test can be performed by checking the blood HCG level 10 days after sexual intercourse and before the menstruation is delayed; you can also use more convenient means of pregnancy test about 7 days after the menstruation is delayed, such as using early pregnancy test paper or pregnancy test stick, the accuracy rate is also high, and a positive result indicates pregnancy. However, to confirm intrauterine pregnancy, an ultrasound test should be performed around 10 days after menstruation, i.e. around 40 days after menopause. After pregnancy is confirmed, regular prenatal checkups should be conducted under the guidance of an obstetrician to understand the development of the fetus, and you should also pay attention to rest, not to strain, and to eat less spicy and stimulating food.