Remarried and feel strange about carrying on my new husbands last name, loss of identity?

i know that when i was growing up my mom kept her married name and never remarried but when she had my brother she wasn't married yet so me and my mom had one last name and my brother had another. we constantly had the question of "are you adopted?" etc. When I married the first time I took his name. Now I divorced and am remarried. I kept my same last name from my last marriage for certain reasons and i talked it over with my husband now. He has 3 children and him and all of them have the same last name and me and my son have our last name. I kept it because if i took my husbands name then their would be 5 of us with the same last name and my son with his last name so he was ok with it. As I said there are other reasons I won't discuss because I can't but that was the main one. I have an understanding husband I suppose. Believe me, I am NOT good friends with my ex either, he absolutely loathes me and I have nothing but animosity towards him. I am only civil because he is the father of my son that's all, lol.