Yes. You can ask your health care provider for a PCR swab test to take home. That way you can swab at the first sign of any lesion ,such as the one that you describe. If they won’t give you a test kit to take home, our clinic can supply you with that kit. You would need to establish care at the clinic for this to occur via a phone consultation.
Yes, I think you could take it again. If it is still indeterminate, then I would ask if you would be interested in participating in a study of an investigational antibody test. I would also make the assumption that you are not infected – that is the standard for how to interpret two indeterminate western blot tests 6 months apart.