I am unmarried and pregnant. Can God ever forgive me?
God certainly can and wholeheartedly desires to forgive you for this and every other sin in your life. First John 1:9 says, "If we confess our sins, he is faithful and just and will forgive us our sins and cleanse us from all unrighteousness." Not only does He want to forgive you, but He also wants to have a loving, fulfilling, intimate relationship with you. He wants to be the fulfillment of all your relationship needs--father, husband and best friend.
You must face the situation you are in. You cannot undo it. But, the Lord can get you through what must seem like very difficult times ahead. You need to seek the counsel of a trusted pastor who can help you decide whether to keep your baby or to place the baby up for adoption. There are many possibilities, so keep an open mind until you seek wise counsel. God has a plan for you, even in the midst of these circumstances. Be prepared to follow His will for you, as difficult as it may be.
You should also begin a daily walk with the Lord, which includes Bible study and prayer. He wants to teach you about himself and guide you into all truth. In His Word, you will learn about God's character and principles for living a Christian life. May God bless you and your little one.