Too soon for pain

Wow - I'm still in the early phases of training and now my knee (right ) is acting weird.  I have never had knee pain before.  I'm not a runner and usually do other types of cardio; I'm basically jogging.  I feel a twinge in it when I sit down.  I try to make sure I always to enough stretching before and after a workout.  I don't know???

Still planning to go to the gym but will just be aware and mindful of pain/discomfort that isn't "normal" - whatever normal is.