I have a child that's father I am not with and I chose to give him his dad's last name out of respect for his family not him. This way he could carry on his family name and if he chooses later in life to go with my last name that is always his choice. I know in massachusetts there are no legal issues that go with a last name. If the father signs the birth certificate he is the dad unless proven otherwise and if he doesn't sign the state will pay for a dna test. I didn't have these problems but am very familiar with the system in mass because I have worked in the legal system for some years. Good luck in your decision my son is now 11 sees his dad regularly and at times wants to change his name to mine but I told him he needs to wait until he's 18 for a final decision because at his age he keeps changing his mind.

I agree with forbiddenxo, use both your names.