Slight leg pain/strain feeling what could this be?

i get slight upper inner thigh pain and my leg feels a bit strained im 16 and will be 17 in 2 days, i thought it could be dvt but i recently went to the doctor for arm and chest pain and they did an ekg and i asked about my leg and the doctor said there doesnt appear to be a bloodclot but then again there was only an ekg done, the pain is on and off in my right leg , since i sometimes get arm pain could it be fibromyalgia and i also smoke marajuana if that could be effecting anything?