Let me introduce you to in-vivo biology.
If PCR finds mRNA snippets in you, then that means youre being fucking infected by viruses which are releasing their genetic code to replicate. qPCR is even cooler, because it at the same time monitors the rate at which genetic material is produced in each cycle of PCR. Now comes the biggest part of my destruction.
The chemical half life of mRNA in vivo is literal fucking minutes. The PCR test preserves genetic material chemically from breakdown. This test is preserved so immediatelly after sampling. Thus, if you dont have virus replicating inside you, you dont find the mRNA.
Ergo - no virus.
Its not an antibody test, and its impossible to find positives from prior infections. Due to the fax mentioned above