Even if the penis is inserted into the vagina with a few jerks, the chances of pregnancy are unlikely, but the possibility of pregnancy cannot be ruled out. This is because when having unprotected sex, even without ejaculation, during the process of sexual excitement, prostatic fluid containing sperm may enter the vagina, and if a woman has a mature egg expelled during this time, there is a possibility of pregnancy. Especially when a woman is ovulating, the chances of pregnancy will be relatively high. Therefore, at any time, the contraceptive method of extracorporeal ejaculation is not reliable. If you do not want to get pregnant, it is better to use condoms and take scientific safety measures before having sex.