I have a pea-sized red spot on my leg, feels indented to the touch. I have had it for 5-8 months it's a faint dark red. When I first got it it came from nowhere, as a scab, I then picked at it a tincy bit - there was a bit of blood and puss. I thought it was a bug bite, I then just left it and it kind of sealed over, and became smooth and slightly shiny. I went to the doctor's and they didn't know what it was, they said to come back in 3 weeks, this was about 3 months ago - I didn't go back because I was busy. I have no idea what it is, and I'm worried that it's infected, please help.