i gave my daughter her father’s last name. that is because if him and i stay together and get married, we will all have the same last name. but if we seperate,and i was to marry another man, then she would have a different last name than me no matter what.
if you don’t name the father on the birth certificate, then give it your last name.
my personal preference is that if the father is going to be a part of his child’s life, then he deserves to have his last name given to the child.