Yes, I believe the right test can differentiate between the different antibody responses, telling you if you reacted to the virus, reacted to the vaccine, or both. I looked into this at one time and think I found one that cost $220. Sorry I don not have the link handy.

If you or anyone could post more info i’d be grateful. Like what specifications to look for in a test.

Also i wonder (approximately) how long after infection it would still be possible to test.

Get an antibody test that's for something other than the spike. If the vaccine you got only has the spike (all EUA/BLA in the US) the vaccine won't boost anything else.

Thanks for your reply, that’s good to know; I got the Pfizer vaccine by the way (only 1 shot.)