When my daughter was showing me her cheerleading moves one day, she was standing straight and looked crooked from the front. I told her to stand straight and she said "I am!"
It turns out she has something called "prominent rib" - her rib is sticking out a little bit. They just gave her an x-ray to make sure nothing was causing the rib to push out. Everything was fine. She's 15 now and she's putting on some weight so it's not so noticeable anymore. The doctor told us that it's somewhat common and almost always is harmless. So hang in there! Or as the above post says, there are lots of lumps and bumps - usually benign!
This could be a cyst , fatty tissue , I expect it is benign its good you are seeing the doctor, relax I know its scary, lots of lumps and bumps on the human body most are benign..let us know what he says ..good luck