OK, so your maiden name was, say, "Jones". Your now husband's birth name is, say, "Smith". You had a child, that you named, "John Jones". You then married your now husband. What is not clear is what you mean when you say "My husband and I have a child...he took my last name." I am presuming you mean the child took your last name, so in this example, your child's last name is "Jones". But do you mean your husband took YOUR lasts name? I.e. Did he change his name to "Jones" from "Smith"?
I look forward to your clarifications.