Ive had a lump in the back area of my neck just below my hairline. I first noticed it4 or 5 months ago, then it was just hardly able to be felt, but now its gotten larger and you can now see it.

Its maybe the size of a pea or little bigger and hard and not able to move it.

Ive made a doctors appoinment but im ubale t oget in untill the 9th of April

What could this be