Right leg feeling like it's about to fall asleep; very uncomfortable. What could this be?

I have a sensation in my leg that you usually get after crossing your legs for too long, or the feeling right before the leg gets tingly, but my leg never gets tingly. I’m concerned this could be a blood clot, or something more serious, or perhaps nothing to worry about. I saw a doctor about it a week ago, but the follow up is in another week while he reviews my full medical records. In the meantime I’m stressing as to what this could possibly be, as I have a hard describing the sensation. Usually walking around seems to relieve discomfort, but it seems to be getting worse and worse each day. Any help would be appreciated.