What Causes A Blood Filled Bump On Inner Thigh?

Hello,
I had a quarter sized purple/ red bump on my inner thigh that started about a month ago. It was hard but then the middle of the bump got soft and got a red blood dot in the middle of it then finally two days ago, it popped. I have been putting polysporin ointment on it and covering it with bandaids. It has left a small pea sized hole in my leg. What was/ is it? I have a doctors appointment in 4 days but am a little worried about it. Will this come back and is there anything else I should be doing?
Jen