Bump with bruising. A lttie worried

About a week ago I noticed some mild pain in my right thigh and teh next day there was a "bump" about the six of a nickel.  The next day it was surrounded by a bruise but the bump in the middle has no bruise.  At has been a week and I thought I better get it looked at. I went into a clinic as my surgeons office is closed.  He seemed a little concerned and asked me to come back Monday for an xray and to have my surgeon fax my recent bloodwork over.   So, have any of you ever heard of something like this happening?  Im hoping I just bumped it and didnt remember, but well see. 

I've never heard of anything like that........I have heard people talk about being prone to brusing when their K levels were low. Could it have been a bug bite?  I know in NY, Lymes disease is very common.  It normally  starts with a bite, and then within the next day or so ....a red circle forms around it.   Once diagnosed, it's treated with agressive antibiotic therapy. But there are a number of things that can cause bruises not related to WLS.....I hope they find out what caused it. Scott