This is a bit odd but I've noticed it more the past few years, whenever I have my period I get upper leg ache. It comes and goes and varies from the front to the back of my thighs, its like a growing pain sort of pain I suppose.
Changing position/hot water bottle eases it, I'm on day one today and it's really giving me grief as I'm sitting trying to work!
I've also been doing leg weights recently for the first time in my life and I wonder if thats causing the pain to be worse for some reason this time.
Anyone else get this?!