ultrasound scan for lump in thigh

I'm 18, female. I've had a pea-sized lump inside my thigh for about 6 months - probably longer but I first noticed it six months back. I went to my GP (twice) when I first noticed it and both doctors felt it and said it was nothing to worry about, just a lipoma or something else. However, over the past two months it has grown increasingly painful and has enlarged slightly, there also seems to be a similar mass forming next to it, though I can't tell if it's part of the original lump or a new one and the skin above it has discoloured slightly. Either way, it got me worried and I went to the GP again before Christmas and was (finally) referred by a nurse for an ultrasound scan which is next week.

So yeah, pretty nervous. 

Will update when I know more.