my advise for all is,
if you want to have sex, make sure you know the consequence of it,
both emotionally and physically.
If you are willingly to deal with the consequence, then you are
mature and mentally prepared for sex.
Even if you used the protection correctly, there is still a slight
chance of STD, pregancy,etc, not to mention the emotional scars.
Even married couples use protection for family planning.
Think it carefully before having sex.
Having said that, once you are mature and mentally prepared,
knowing abt contraception and sex is essential.
take care !