Last name help!!

So my boyfriend and I are having alittle boy in less than a week & im still having trouble choosing what last name to give him!! Originally I was going to give him my boyfriends last name but I've thought more about it & I just don't know! We have a good relationship but there have been some little issues that makes me unsure if we will be together forever.. But then I also feel like babies should have their fathers last name if the guy is in their life & will be a good dad.. Ugh any advice or personal experiences with this would help!