Am I wrong for refusing to give his last name?

I left my fiancé a week and a half ago, so we are not together or living together. He wants us to get back together but frankly I don’t see that happening.

Im pregnant and due in March. He is adamant that he wants the baby to have his last name. He used to tell me it was a deal breaker. We’d been engaged, not married. I had told him from the beginning, back when we were still dating and talking marriage, I was fine changing my last name as long as it was before I started my career. In the career I want you are known by your last name, so once I was in I would not be changing my last name or risking setbacks to furthering my career. At the time it was years away, but now I should be starting within the next 1-2 years. So even in the unlikely event we do get back together, I won’t be taking his last name.

As for naming the baby, he still wants the baby to have his last name. However, we’re not even together. He’s been very uninvolved in my pregnancy from the beginning. I’ve done everything alone which played at least a small part in me leaving. He wants us to get back together but if we don’t he’s saying he does want split custody. I’ve offered to compromise on the last name and hyphenate it. I’m not a fan of hyphenated names, but the child would have both our names then and they could choose when they were 18 or got married which name they actually want to keep on.

He’s refusing saying hyphenated names are stupid, it’s his kid so they should have his last name and it’s like he’s not even registering my feelings on the matter. He used to always try to stalemate me into situations like he didn’t like doing dishes, so he just wouldn’t do them. If I wanted them clean I could clean them. Same with yard work, and tons of more serious issues. Essentially he refused to ever work through issues, communicate properly, or compromise, and would just try to force me into the decision he wanted me to make. He keeps acting like it’s “laughable” that the child would have my last name - despite the fact that I’ve been alone for this pregnancy and in my opinion he’s done nothing but actually get me pregnant, and we’re not together.

Am I wrong to make this an issue? I don’t want my child to have a completely different last name than me. I thought the hyphenated name was a completely fair compromise, that way the child would have both their mom and dad’s names and the choice would be up to them if they eventually wanted to keep just one name.