Hi, tonight when I was putting lotion on, I noticed two black spots in my butt crack area near my coccyx. I thought I had pooped myself but when I went to wipe it, nothing came off. It looks like a bruise, but a dark color. Due to a program I was in, I recently spent a lot of time in grass, and unfortunately ants as well, so I have quite a few bug bites. What is this?