Black elevated bump on my l..

Ive had it for 2 years. I have seen 2 regular doctors and 1 derm and the derm said its not cancer and it changes from skin tone to black because of blood in it or somthing. The last 2 days it has elevated off my thigh and is black again. It is also a little tender to the touch it feels like a hard scab almost and I dont know exactly what this is doc didnt tell me. My mom wantz me 2 go 2 the emergency room but i dont have any insurance. If anyone can find any info on this or have had somthing like this please share info. The ONLY reason im freaking out cuz it has OBVIOUSLY gotten bigger and DEF. ELEVATED off my thigh ALOT its not flat like it usually was (it might be a little bump but not LIKE THIS)

It changes colors, its on my thigh, irregular shape for 2 years NOW its a little tender and really elevated off my leg, hard like a scab, and black. Please help!

I used to work as a nurse. For God's sake, find a free clinic or call a University hospital, such as UCI in Southern Calif. You MUST have this re-checked immediately!! If you aren't satisfied with what the first three Dr.s told you (I WOULDN"T BE!!!) then continue to SEEK MEDICAL HELP!!! Start making calls tomorrow morning, PLEASE! I've never heard of or seen anything like you describe!! Be very DETERMINED to find out what's REALLY going on!!! There are low cost clinics too.