How can I tell if I was asymptomatic with COVID?

I’m fully vaccinated and boosted. I gave blood a couple of weeks ago and was sent the results of an antigen test that said that I was positive which meant that I had either had COVID or was vaccinated. This isn’t particularly useful information since I know that I was vaccinated. Is there a test that can tell the difference?

Serum antibody tests which check specifically for viral capsule antibodies would show whether you had been infected, since vaccination only produces viral spike antibodies.

I assume most antibody tests focus on spike protein AB detection, for whatever reasons. My understanding is that this is the antibody titer that best reflects prompt immunity.

In a previous thread I saw some confusion about “rapid antigen” tests, which some people think is testing for an immune response, but which is actually testing for viral proteins. An “antigen” is a thing your immune system reacts to. In the case of a covid antigen, it’s part of the covid virus. Are you sure that the results of the test you got were testing for immune response and would show a positive for anyone vaccinated?

What value is there in testing donated blood to see whether someone is vaccinated? A majority of people are vaccinated, so it’s not like they could do anything useful with a positive result.

My mistake. It was an antibody test, not antigen. I still don’t see the benefit of it to the vaccinated.

Blood donation centers started giving antibody tests instead of movie tickets almost 2 years ago, when there was no vaccine. I’ll admit, I was hopeful for a positive result. Those tests don’t make as much sense anymore, and my local place has switched to a different incentive.

Any idea what those tests cost? I have been such a bundle of anxiety at the prospect that I might get really sick if infected that I have literally been taking sporadic anti-anxiety meds. OTOH my dad, the now 81-year-old asthmatic, was apparently infected pre-vaccine and had absolutely zero symptoms. If the test isn’t crazy expensive, I might even be willing to pay out of pocket because it would REALLY take a load off my mind if I discovered I’d contracted COVID at some point and never knew.