I bought a domain and a few days to a week later a trademark was issued on the same name. should I have anything to worry about or does the trademark holder have to worry about me?
as long as you owned it (and can prove that) before the trademark was granted (filed?) I think you are in the clear... you'd be better of consulting a lawyer on this one though...
First to use, not file, have prior usage rights. The date of the trademark filing makes no difference - if someone was using the mark before you, and the usage is in the same classification, they can claim infringement.