I've gone bare many times when I shouldn't have. I've got burned (or The burn) a couple of times. Some things may not show symptoms and some things are not testable / detectable in men but you can still be carrying it. Is definitely a risk, but the whole not feeling well for a couple of weeks I don't think that's anything STI related. If you feel anything from that it will be more acute and should involved sores / discharge / burning sensation if you are having any symptoms at all.
