I've been having bruise like pain in my upper legs on the outsides but there is no bruise. has nothing to do with physical activity. ?

Not enough info: For accurate suggested diagnosis. At first thought, it sounds like you may have trochanteric bursitis, but this would be rare to have bilateral in a young person, but definitely possible. Is it painful at night when you lay on your side? You would probably benefit from a physical exam and thorough history to give the most accurate diagnosis, but that would be my first thought from what you said.