Do I need a DBA for my domain name?
If you want to conduct business using the domain name, you would indeed have to register it as a D.B.A.
Please keep in mind that in many states, a D.B.A. is limited to conducting business in it's county of designation. Any other county you would want to branch business into would require a new D.B.A. registration. Additionally, some states such as Kansas, Mississippi and South Carolina do not offer any D.B.A. service at all.
If you live in California, Florida, Georgia, Illinois, Minnesota, Nebraska or Pennsylvania, publications will be a requirement for each D.B.A., so that is also something worth considering, depending on your business plan. It may be worth using your Corporation to open another entity (another Corporation or LLC).
That being said, I always recommend consulting a professional accountant to discuss these options to find what will best suit your business aspirations.
I hope this answer was of some help.