During s**, you wear the condom on your p**** to prevent semen and s**** from entering your partner’s body when you ejaculate (come). Semen can carry STIs. It also contains s****. If s**** goes inside a v***** there’s a chance it could meet with an egg and lead to pregnancy.

Condoms do not work as well at preventing pregnancy as some other forms of birth control. However, using a condom is much better than not using birth control at all. Some condoms contain substances that kill s****, called a s*********. These may work slightly better to prevent pregnancy.

If you use condoms perfectly every single time you have s**, they’re 98% effective at preventing pregnancy. But people aren’t perfect, so in real life condoms are about 87% effective — that means about 13 out of 100 people who use condoms as their only birth control method will get pregnant each year.