There is no chance of pregnancy during intercourse if you use external ejaculation as a form of contraception. The sperm must remain in the vagina and pass through the cervix and uterus to the fallopian tubes where it can unite with the egg to form a fertilized egg. However, if a man has sperm loss or premature ejaculation, it is not possible to ensure the safety of contraception. Therefore, if the above conditions exist, you can take some emergency contraception after intercourse, such as oral emergency contraceptive pills, the use of emergency intrauterine device, or oral mifepristone within 120 hours after intercourse, can achieve the effect of emergency contraception.