6 wks ago i got concussion & 3 in cut on head. no ct/tetanus done & now having pressure headaches over a week. should i be concerned? cut from metal

Depends how severe: I'm not sure exactly what your symptoms were as far as "concussion". If the injury was significant enough to actually knock you unconscious for a while, then I do feel that a head CT or MRI would be warranted. The main thing to exclude is any bleeding inside, such as a subarachnoid or subdural hemorrhage. My guess is that it's more likely not the case, but I would still have it done to be safe