I have hair down to the middle of my back and haven't noticed any loss. So, it could be your meds. I also read recently, that it isn't good to wrap your head in a towel too long after shampooing. (I can't remember why or where I read that). I have noticed that I don't have to shave my legs everyday when I am having an 'RSD surge'....it just doesn't grow! (which isn't a bad thing! hee hee)
Check with your pharmacist....I think that is the best thing to do.