Sperm are characterized by higher motility and can enter the cervix through the vaginal opening. Higher sperm count in semen and sperm with higher mobility can enter into the inside of the cervix through the vaginal opening, just that the possibility of successfully entering the cervix through the vaginal opening is lower than that of entering the cervix from the inside of the vagina, but there is still a certain chance of conception. Therefore if you are not planning to conceive, you need to take adequate precautions when having sex. Therefore, sperm can enter the cervix through the vaginal opening. If you have unprotected sex and notice symptoms of suspected pregnancy such as delayed menstruation, it is recommended that you go to the hospital in a timely manner to complete the relevant examinations and make a clear choice of whether or not you are pregnant.