Hmm.. What is the pledge again? I will not have any sexual relationship before marriage, or I will stay true and loyal to one partner? Many keep saying that our mind draws only toward what we think, not away from it. Thinking ‘I will not’ or ‘I shall not’ is going to do put you exactly where you will not.
Oh, but this is old thought already. You already ‘KNEW’ and tried this.
A research report at MSBN, quotes,
“Teenagers who pledge to remain virgins until marriage are just as likely to have premarital sex as those who do not promise abstinence and are significantly less likely to use condoms and other forms of birth control when they do..”
Read more here. (Link) MSBN, Study: Teenage 'virginity pledges' are ineffective