@Eva,
Eva is also incorrect.
Condoms have a 98% effectiveness rate according to
Planned Parenthood if used correctly. This means that out of 100 couples who use condoms correctly for 1 year, 2 of them will have a pregnancy. Used incorrectly, they have an 85% effectiveness.
There are other forms of birth control, for example the pill, which are much more effective (more then 99% effective) assuming you take them every day and don't forget. One issue with the birth control pill is that they don't stop STDs. And of course there is nothing wrong with using both the pill and condoms which will decrease the chances of both diseases and pregnancy.
That being said, I think 14 is a little young. I don't think anonymous adults should be so prudish to think it doesn't happen. I agree with Eva that if you are going to start, you should think about and discuss the possibility of a pregnancy. This is a discussion that I had with my partners when I was in my 20s.
I won't tell you whether you should or shouldn't have sex, and I don't think that anyone who doesn't know you personally could ever give good advice on this.
I do hope you have some understanding adult who you can talk to about this, maybe a doctor, or a school counselor? The high school where my kids go provides family planning services where kids can get very good, non-judgmental advice on birth control and relationship issues.