I Think I Overextended My Leg Muscles Doing Stretching Exercises,

I think I overextended my leg muscles doing stretching exercises, and am hoping that's all it is. I have pain in my leg from my thigh to my ankle which is not too bad during the day but gets worse at night. No swelling, no restriction of movement. It has been going on for almost two weeks. Should I be concerned? I am an almost 75-year old woman. I direct a strength and balance group of seniors and was demonstrating exercises a little too vigorously. Felt all right until the next morning.