Contraception is used to prevent (‘contra’) conception and a resulting pregnancy.
When you have intercourse and don’t use a good method of birth control you run the risk of an unwanted pregnancy. So if you don’t want to become a parent (yet), you have to use contraception every time you fuck! You have to decide on a method of birth control before you start sex: don’t think the first time doesn’t matter!
Some methods to choose from are Birth Control Pills, condom, female condom, IUD, Nuvaring, an hormonal implant, Depo-Provera, a diaphragm or IUS.
There are also some other methods, but these are not very reliable, like The Calendar Method, Withdrawal and The Billingsmethod.
The safest way to have sex is combining a birth control method with condoms. This protects you both against pregnancy and STD’s. If you combine oral contraceptives with a condom it’s called ‘Double Dutch.’

How reliable are the various contraceptives?

When we’ll have sex for the first time when do I start talking about contraceptives?

Emergency: I had sex but didn’t use birth control. What can I still do to prevent pregnancy?