My knee hurts, its been for 1 week?

im 15,
its been hurting for 3 weeks, i would do bleachers, squats, power cleans, and it
would hurt after but slightly. and then it would go away.
But last week i tried to squat but i couldnt it hurt TOO much
now when i run it hurts a little, and i cant squat or anything cause it would
hurt.
i let it rest for a week but it still hurts.
what's wrong?
It could be Runner's Knee. My brother, who is 16 was just told he had it. Look
up Runner's Knee and see if it matches your symptoms. But really, it's not that
serious, and is actually pretty common for teens and adults.

Try to follow R.I.C.E.: Rest, Ice, Compression, and Elevation.
Maybe its time you should go see a Dr.