You cannot get pregnant on the third day of your period. This is because the endometrium is still peeling on the third day of menstruation and the level of estrogen and progesterone in the patient’s body is very low. In this case, it is impossible for the follicles to develop and it is difficult for the sperm to enter the uterine cavity of the woman. It is possible that the sperm will be washed away in the vagina or in the cervical canal, so the chances of pregnancy in this case are almost non-existent. However, intercourse during this period of time can have a great impact on the woman, because intercourse with a loose cervix and blood in the vagina is particularly likely to lead to infection. If the infection goes upstream and causes infection in the uterine cavity or the fallopian tubes, it may lead to damage to the endometrium, adhesions to the endometrium or adhesions to the fallopian tubes. This not only affects the health of the patient, but also affects her conception.