Help? TMI

I have a weird bump on the small of my back, right above my butt. Its been there a few days now and it's getting bigger. It feels like a pimple, but when I tried popping it, it bled a lot and then shrunk a little bit, but it's still there...I tried googling it. I'm positive it's not an STD of any sort, and it's not a bug bite.

Any ideas on what it could be?