Fathers last name ?

Hi I need some insight here , I have been reading a lot of people's opinions online about giving your child your last name if your not with the father , but I am still torn ... See we are not together and have not been since about 13 weeks .. He has never said get a abortion and he is very proud and excited for his son to arrive , I mean he could turn around and not be involved I just can't predict the future but for now he says he wants to be 100% involved .. He wants me to give him his first name and last name because it is a family tradition , but I am not going to give my son his first name I have decided that . Still torn between giving him my lastname or his fathers ? I am leaning towards his fathers even though we aren't together I still want him to have a bond and connection with his father and I would never take that away from either of them . Any thoughts ?  Thanks ladies