Sorry I never updated this in a timely manner. I'm fine!!!

I went to the doc-in-the-box as planned, and they didn't actually give me anything. They just said it was good that I came in because it did appear to be a spider bite, but it doesn't look like it needs any medical treatment. Oookay.

I thought it was kind of weird that they didn't suggest anything besides watching it closely, but thankfully they were right. Nothing has happened or worsened except a lot more bruising that varied a lot in color, size, and severity. It hurt for a few days as well. Now it's just a black circle and it appears to be healing a lot.