I think i might have pulled a muscle?

i was doing squats and lunges last night at the gym with free weights, woke up and my left outter side of my thigh all the way down to my knee hurts. Painful to walk. I cant pinpoint the exact place that it hurts. Doesnt hurt when i bend my knee so i know i didnt injure that so im guessing i must have pulled a muscle somewhere in my leg?? and if so how long will it take to heal before going back to the gym?