You were given an answer in your last post why did you even get an RNA test done you have a negative 8 week antibody you could just wait 4 more weeks and get your 3 month negative which is conclusive. No you do not need to test out to 6 months, a 3 month negative is considered conclusive. If your doctor ordered your RNA test what did he tell you about it he is better suited to answer that question. Get you 3 month negative and then move on.