Many colleges have day cares on campus now because of changing times a lot of students start college already having children. As far as your boyfriend asking you to marry him it depends on if you love him enough to want to marry him you have been dating for several years so it's not like you are strangers and don't know each other, remember that you are the one that has to carry the baby so the final decision is yours but there are other options if you don't want to get an abortion or consider adoption. Check into on campus day cares financial aide will help you pay for it, also some outside day cares have aide to help single parents. Don't get married if you are not ready for that type of commitment or you feel your boyfriend isn't ready for such a commitment.
Maybe talk to your schools guidance counselor also they may be able to give you more options. Just don't feel obligated just because you are pregnant to get married but if you love your boyfriend and you feel that he loves you and you were planning a future with him anyway maybe still consider the possibility of marriage you can still stay in school and do all of that, there are people who have done it and Graduated college with a degree. You're at an okay age to have a child it just wasn't in your plans right now.