Don't dump him unless you know that your love and affection is stronger than his toward you. You can be in a committed relationship without marriage. He could have some very logical reasons for changing his mind that may have nothing to do with feeling less seriously about you. Remember your child as well. It's never good to stay in a relationship solely for a child, but you shouldn't be so rash in making such a decision when a child's best interest is at stake.

Sounds as though you two need to speak about the feelings that exist between both of you rather than marriage.