Ready for marriage

My boyfriend and I have been together for a little over 4 years, living together for 2 years, and now have a 4 month old. The other day I told him that if I got this new job I applied for that I want to start saving some money to get married. I don’t like having to introduce my child as having a different last name than me, I gave her his last name because I thought that eventually I would have it too. I know it’s silly but I feel like when I say she has a different last name than I do some people don’t see me as her real mom.

He just brushed it off after I told him that I want to start saving money and we haven’t talked about it since. Am I making a bigger deal out of this than it needs to be? I don’t want to pressure him into it but I also want to be a family. How can I tell him that it’s important to me without pressuring him into marriage?