How To Treat Pain And Soreness Behind The Knee Due To An Injury?

I am 28 yrs old. I slipt and fell forward on a steep hill and my leg closed hard and awkward and i felt pain on the front of my knee. There is no swelling or instability, but i feel soreness behind the knee and when i bend my leg closed i feel discomfort behind the knee. I have iced it and stretched. Still some discomfort behind knee. Should i get it looked at or is it a simple sprain?