How long do strained knee ligaments take to heal??

The inside of my left knee has been sore for about a week now. My knees have not been the best for 2-3 years but after I painted most of the outside of our house, it started aching pretty good. There is no swelling but if I MASH on a certain spot, I can feel it. I haven't taken anything for it like Motrin but maybe I should?

Looking for advice before I consider making that Ortho Call (HATE those places)