Condoms, when used correctly, have a 2% chance of pregnancy. But in clinical work there are couples who use condoms can also get pregnant, these are not used correctly, thus leading to the chance of pregnancy can reach 15%. There are mainly the following situations: 1, not every time you use, many couples combine the condom with the safety period, to the safety period does not use the condom, resulting in the occurrence of pregnancy. In fact, for women the safe period is not safe, it is best to use condoms every time to prevent pregnancy. 2, to use only when ejaculation, this method is also wrong, because the male ejaculation has a small amount of prostatic fluid into the female vagina, there is a small amount of sperm inside easy to make women pregnant. 3, before placing the condom is not clean the front of the small air sac, easy to lead to the rupture of the condom, these are These are the reasons for using condoms but getting pregnant.