How to prevent knee injury

I have been running for years but never did I feel any pain in my knees . I have been working with fitness blender for the past couple of months now .. but as my strength and flexibility increases , I have begun to feel pain in my knees on squatting . I am terrified for my knees ! I am just 25 after all . And not really overweight .. any suggestions ? Should I switch to low impact ?? But I love jumping !