Should I get married?

I am 18 years old and my boyfriend is 21. We have been dating for 2 and half years off and on. He is now a Marine. He asked me if I wanted to marry him and i said yes because I love him. He keeps saying that he wants to marry me or he is not geting married at all. Well he wants to get married in the next few days by the judy and have a wedding later because with him being in the Marines he gets more money and we were going to save up that money to pay for own wedding and for an apartment for me in CA while we go to school. I don't know what to do. I love him but i don't know if i want to get married right now. I know that I want to marry him in the futher and if we do this now it will be a good thing because we will have more money for the futher but I don't know. Help me!