Abortion marriage contract?

My boyfriend says if I abort my baby then he will marry me and we will start a family. He says God does not like births out of marriage, so it is sinful for us to have baby. But I'm worried that he is just saying that so I get an abortion and then he'll leave me. Is there some kind of contract I can make him sign saying that if I get an abortion he has to marry me and have a baby after we get married?