Am i ready to be engaged?

i am only 19 years old. I have been with my boyfriend for 4 years now and we have a beautiful 1 year old son. we have never broken up. we have our fights, but we work them out. we both go to college and work and still mke time for our relationship and our new family. to me its all great. but he says he thinks it is too much and doest ever want to get married anyway. but marriage is something i want. i dont know what to do.