I have a growing lump three inches under collar bone I believe to high to be cancer could it be?

Get it seen. This is too big to be a normal node. You're wrong about location ruling out cancer. At your age, it's Hodgkin's until proved otherwise.
Yes. Better to have any new lump checked out. Also notice how fast it grows the bigger it gets needs a faster diagnosis.
Maybe. You are pretty young to develop cancer. Nevertheless, you should have a doctor check it out.