You can give the child whatever last name. I am giving my daughter my boyfriends last name. If he wasnt going to be in her life I would give her mine but we do plan on getting married so I don't see the point in doing one and changing it in a year or so. Even if we weren't together and he was involved I would give the child his last name.
My fiance and I have had this discussion a lot. You have every right to have the baby have your last name and not his. But you should both try to agree on it. My fiance and I decided that since we will eventually get married it would just be easier to give the baby his last name. Changing it later, while it can be done, can be a complicated process so if you think you are going to marry him I would just give the baby his last name.
Thats totally up to you. U can give him your for now if you want and since the dad will already be on the birth certificate it wont cost you anything to get it changed later when your married. Thats what I did with my first and as soon as I got married I just took the birth certificate to the social security office and I got the social changed and later the birth certificate.