I have worn a purity ring for nearly a year now, and I can honestly say that it is not about the ring at all. It is something to pray on very hard. In the begining I failed miserably. But once my relationship with God was restored and grew, I found my ring wasnt the thing of importance, but the covenant you enter into with God. A promise and a very awesome goal of no sex before marrige or in my case never again until marrige. However you should spend quite some time praying over this, it is biblical to remain a virgin untill marrige. Here are some verses from the Bible that talk about sexuality and sexual immorality. Read these and study hard and make the decision based on your level of self controle. ask yourself if the ring would be a good reminder to you or not. For me at this point, it helps me stay focused, but I also no longer put myself in a position to be tempted physically, but remember it isnt just physical things that can be immorality, but also the lustfull thoughts..
Flee from sexual immorality. All other sins people commit are outside their bodies, but those who sin sexually sin against their own bodies. Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price. Therefore honor God with your bodies. (TNIV, 1 Corinthians 6:18-20)
It is God's will that you should be sanctified: that you should avoid sexual immorality; that each of you should learn to control your own body in a way that is holy and honorable, not in passionate lust like the pagans, who do not know God; (TNIV, 1 Thessalonians 4:3-5)
Now concerning the matters about which you wrote: “It is good for a man not to have sexual relations with a woman.” But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband. The husband should give to his wife her conjugal rights, and likewise the wife to her husband. For the wife does not have authority over her own body, but the husband does. Likewise the husband does not have authority over his own body, but the wife does. Do not deprive one another, except perhaps by agreement for a limited time, that you may devote yourselves to prayer; but then come together again, so that Satan may not tempt you because of your lack of self-control. (English Standard Version, 1 Corinthians 7:1-5)