3 Ways to prevent unwanted preg*nant, If you can do number 3 you will never get preg*nant in boyfriend and girlfriend relationship,CLICK TO READ

About 85% of s**xually active women who do not use co*traceptives become pr*gnant within a year. A woman can become pr*gnant while bre*stfee*ding, from about 10 days after chi*d birth, and even during her m*nstrua tion.

1. Total Ab*tinen*ce
2. Use of contr*acep*tives
If you are s* xually active and do not want to get pr*egn*ant, always use contraception.
3. What you can do to avoid unwanted pr*gnancy. This guide will help inform you.
Steps

Don't give in to peer pressure. Many teenagers can feel left out/behind when their friends start to have boyfriends, or start having s*x. Those who have started to do these things early can often talk about it enough to make others feel left out. However, if you do stand your ground and wait until you know you are ready, you will be glad of it. It means you'll have waited for the right person and the right time.
Everyone develops at different rates, both physically and mentally, so don't feel that you should be racing your peers for things like having s*x and getting boyfriends.
Many of your peers will regret their choices in time. Others could even be lying.
Don't just start having s*x because other people are if you aren't ready to do it yourself.
Learn to say "No". This includes saying no to anything you feel uncomfortable with. Whether it's refusing to have a boyfriend, have any kind of physical contact, have s*x or have s*x without protection, there is nothing wrong with standing up for yourself.

The only 100% safe way to avoid pr*gnancy is to not have se)*x, so you shouldn't feel st*pid for not wanting to go through with something.
Know what will and won't result in pr*gnancy. With s*x in general, there are a lot of myths about what will get you pr*gnant and what will keep you from getting pr*gnant. A lot of these myths are simple misinformation, and some of them are lies designed to deceive you. Arm yourself with the facts and lower your chances of preg*:nancy the safe, smart way.
Unprotected v*ginal s*x has the highest likelihood of resulting in pr*gnancy. Male sperm fertilizes the fem*ale eg*g, resulting
in the growth of a fetus. Unprotected s*x also carries a high risk of dis*ase and infection.