How to print only the created columns in Sharepoint using JavaScript

I need to print only the column that has been created by me.

function retrieveFieldsOfListView(listTitle,viewName){

   var context = new SP.ClientContext.get_current();
   var web = context.get_web();
   var list = web.get_lists().getByTitle(listTitle);
   var listFields = list.get_fields();
   context.load(listFields);
   context.executeQueryAsync(printFieldNames,onError);


   function printFieldNames() {
      var e = listFields.getEnumerator();
      while (e.moveNext()) {
         var fieldName = e.get_title();
         console.log(fieldName);
      }
   }

   function onError(sender,args)
   {
      console.log(args.get_message());
   }

    }

But this code is printing all the pre-defined fields along with my field. I don't want the pre-defined fields like 'modified,created,etc'. I want only the coding changes. UI changes are not upto me.