I had an exposure in Dec ’19. I experienced what i thought was a seroconversion illness. I also experienced other symptoms some months after including gum disease and cold sores (which I’d never have before). I have had arthritis symptoms including tarsal tunnel and bony lumps on fingers.

Obviously i was concerned and scared re HIV but 8 months post exposure i took a Biosure self test which was negative. I did this with a friend who confirmed we’d done it correctly and control line was visible. Prior to this we’d attempted another test (not biosure) which failed.

I think blood from the same finger was used for both tests. Could it be that there weren’t enough detectable antibodies in blood for 2nd test due to obtaining blood for 1st test that failed? I know its sounds unlikely that ig HIV positive a detectable level of antibodies would only be present in a tiny amount of blood but could this have caused a false negative result? Is there anything else that could’ve caused a false negative outside of the window period?

Would the presence of another STD, such as syphilis impact upon the test’s ability to detect antibodies? I am not on prep ot did not take pep.

Advise welcome as i have ongoing symptoms that concern me, thank you.