While it's great to explain the benefits of abstinence, Christians have begun to rely too heavily on a shame-based rhetoric that motivates teens into compliance for fear of being "dirty" or undesirable. I cannot tell you how many women I have counseled who became sexually active in their teen years and consequently felt like they were damaged goods.
The FDA has given approval to make the pill known as Plan B available to teens age 15 and over on an over the counter basis and without a prescription. This will be put into place almost immediately. This pill is taken after sex when an individual is concerned that they may be at risk for pregnancy.