Yeah, I agree in a way. I just don't recommend people marrying JUST because they're pregnant.
Tell him if you are not married when the baby is born then you would only feel right to give the baby your name. I would only give my baby my name but we are married. My husband insisted we get married when he found out i was pregnant because he knew I intended to give the baby my name and raise the baby my way no exceptions and no negotiations... I am kinda sorry I married him now it's been 9 years almost.
My husband and I have a 12yr gap as well. If you're really serious and think he is l, give your son his name.. it will be yours too!! :-)