You didn't say how old you are. Certainly your age is a big factor. There is different advice for a 14 year old than for an 18 year old. Nevertheless it is good that you have asked for advice...that means you are intelligently thinking about what to do. Such consideration must also have you consider the future...ask yourself these questions...
1) Did I want to save myself for the man that I marry?
2) How will I feel if I do this and we break up soon after?
3) Do I know how to protect myself?
4) What if I get pregnant?
5) Am I really in love enough to do this? Or am I just curious because everybody else is doing it?
6) Is there anything about my boyfriend that I can't stand?
7) Do I have good self-esteem and self-respect that I rely on to help me make good personal decisions?
8) What will my parents think?
There is some things to think about...always be true to yourself first...be careful with decisions that could affect the rest of your life... Always strive to be smart, not stupid!