I sincerely hope you won't give in to your boyfriend's pleas. After all, if he truly loves you and respects you, he will honor your intention to delay sexual relations until marriage. But if he doesn't honor it, how can you be sure he truly loves you? The answer is - you can't.
God takes marriage very seriously; after all, He gave it to us, and He meant for it to be a source of great happiness and security for us. At the very beginning of the human race, God declared, "It is not good for the man to be alone" (Genesis 2:18). And one of the ways He gave for husbands and wives to express their love for each other is through the gift of sexual relations. Marriage involves the solemn commitment of a man and woman to each other - and in God's plan their sexual relationship is a sign of that exclusive commitment.
But when God's gift of sex is practiced outside of the commitment of marriage, then God's purposes are not fulfilled. Sex becomes something selfish instead of what God intended it to be: a mutual expression of love. The Bible says, "Keep yourself pure" (1 Timothy 5:22).
Put God's will first in your life. He loves you and knows what is best for you. Begin by asking Christ to come into your life, and then commit your future - including your marriage - into His hands.