Whenever some test results turns out to be positive/unexpected our brain starts to think what if it's a false positive? And that's completely a normal thinking according to psychology but one cannot deny something is positive, when they simply gut-guess it, if you really think that there's no way for you to get in contact with that virus, then you can repeat the test, a repeat test to be false is rare in your case as you already have some symptoms,yet of you wanna try, you can always try at a different set up. Recent coco's spikes, chances of spread, normal oral microbiome and several other factors can be considered, but eventually you have to accept the fact and quarantine yourself and safeguard others, would be my opinion, in short!
Next Steps
Repeat and repost! - acts a guide
Health Tips
Relax it's nothing!