Thigh Pain After A Run. Got Over Shin Splints. What Can I Do Now?

Hi I m a 17 year old, female ,long distance runner (half marathons ect). Recently on a long run, my inner thigh near the knee started to ache a bit. This sort of thing is very routine for me and I did some quad stretches and was on my way again. Having many painful injuries before,I have become very pain resilient so I probably unknowingly ignored the ache and finished my run. However post run, I noticed that there was a small and sharp tug in my lower inner thigh whenever I walked. I optimistically figured that it would go away like any other muscle ache after a good nights rest but after two days of no running , the pain is persisting (mysteriously goes away running uphill, downhill and up and down stairs). I asked a knowledgeable runner friend and he said it might be the Vastus Medialis muscle. As of today I can jump around, flex the area, do squats , generally anything that might seems painful for the area. There is also no redness and there seems to be no obvious swelling (but I ve been taking alieve twice a day). If the pain is persisting for two days, do I have a tear or is it just a bad pull? I just want some peace of mind. I literally just got over shin splints almost less than two weeks ago and I ve been battling series muscle and tendon issues all year. very frustrating. Thank you so much and sorry about the long message!