If your unborn's father hasn't been in the picture throughout almost the whole Pregnancy and now all…

I wouldn't. I had that same issue gave my daughter his last name and now he's out of the picture again. Its a decision I really regret. :/

Honestly...no. Because does the baby having his last name mean he'll actually be around?? That's not something I'd want to be upset about or regret later

No because he could just disappear again and once the baby becomes school age having his last name might mean you'll have to ask his permission for certain things (school things) just because of the last name

Nope! You're not married. My ex isn't getting that wish.. No matter how hard he begs. That way you can also control a lot. Like @emkasting said school and appointments he will need proof rather than just being able to take his kid and go. I also believe it's a respect thing so my son will always have my last name and carry on the family tradition. Even if my ex and I were on good terms my son would get my family's name.

NO

I'm glad you asked this because I'm personally going through the same thing right now. I don't know what I should do.

I did. But it's 100% up to you. You can always change it too. and I think it's free for the first year or something like that if you change your mind.

If you aren't married I'd say no. My older sister has three kids, all with different last, none with hers. None of the dads are in the picture anymore. :\

Hell no!

My kids all have their fathers last name. I think it's a personal choice. Sometimes I am frustrated when dads flake because I could have just given them my last name and been done with it. However, I chose to lay down with him and the kids are a product of him. He deserves to have his last name attached to them.

Just my opinion