You won't ARS symptoms at 9 weeks. Symptoms or lack there of will never tell you your status. It common for women that are pregnant to have false positives.
An antibody test at 9 weeks is 99% accurate and the chances it will then turn positive at 12/13 weeks is around zero chance.If you had ARS symptoms your test would be positive at 9 weeks.It really puts you in the clear,that is if you even had a risk at all.