More than likely you are just fine. Pregnancy can take quite some time to happen. Many adult couples will find it can take a year, sometimes longer....and that is when they are trying to have a baby. It is very individual. Some people get pregnant the first month, some take a long time. Some try various methods to become pregnant, others find it happens when they least expect it.
Since you don't want to become pregnant, please stop having unprotected sex. Don't let your being curious cause you to get into a situation of having to grow up fast.
Pregnancy at your age can be dangerous to you and to a baby. Obviously you would not be able to support a child if you were to become pregnant, so do take precautions. Discuss birth control with a parent or trusted adult. Or see your doctor to discuss it. Do Not allow anyone to have sex with you unless they use a condom.....at all times. It can't be where it is put on after he has been inside you for awhile, it can't be where he ejaculates outside of you and then re-enters. Every single time a condom must be worn. If a guy refuses to use a condom, or gives you some excuse as to why he can't or won't, he is thinking of himself and not of your well being.
Ideally you will stop having sex until you are in a position to properly have and raise a child, but if that isn't going to happen, then at least be smart about it and protect yourself so the odds are less likely for it to happen.