Herald:Andy points out, in Psalm 139, David recognized that life begins before birth. "For you created my inmost being;you knit me together in my mother’s womb.I praise you because I am fearfully and wonderfully made.." That is the Judeo/Christian belief or tradition. If life begins before birth then,"Thou shalt not murder" extends to the unborn.
Having an unwanted pregnancy is nothing new. A Christian "walks by faith not by sight". You don't sin a second time to cover the first sin. You repent and accept the consequences for your behavior, give your life to Jesus and let him "who began a good work in you...be faithful to complete it in you."
Once you give your life to Jesus it isn't your life anymore. Trust and obey.