Normally when I sustain a bruise, I have a pretty good idea of how I got it. Not so with this one on my bicep. I have had it since last weekend and cannot think of something that would have caused it. Soccer is the obvious choice but the near perfect circular shape is inconsistent with the kinds that I have experienced in the past. Jeanine thinks I got it while clearing vegetation from around our air conditioners. While doing so, I was stung by a bumble bee, once on the neck and once on the face. I made a rapid exit from the area through thick brush and may have been poked by a branch in the process.