Condoms are a safer form of birth control and can be 98% effective as long as they are used throughout. But there are people who wear condoms also have pregnancy. The specific reasons for this are as follows: 1. Not wearing a condom throughout sex, but using it only when halfway through. Because a small amount of sperm within the secretion before, there is sperm may be pregnant. Halfway through sex and then use, indicating that there is no contraception; 2, condoms are divided into numbers, there are large, medium and small, if the number is not chosen correctly, when wearing a small number can break, if the number is large can fall off, semen will flow into the vagina, thus causing accidental pregnancy; 3, condoms expired, has appeared sticky; 4, before using the condom open when accidentally cut, causing semen leakage; so in the sex life When you have sex, you should check whether the condom is breathable, whether it is broken and whether it has expired. When the condom is found to have fallen off or broken, and it is in the middle of a woman’s period, you can take the emergency contraceptive pill as a remedial measure to achieve double insurance. However, it is not recommended to take the emergency contraceptive pill frequently, but once in a while. In fact condoms can be more than 90% effective as long as they are worn safely throughout and used correctly.