I Am Unable To Bear Weight On Right Leg -

I am unable to bear weight on right leg - this came on sudden as I was getting out of my car I went to stand and got sudden pain in my right upper thigh when I put weight on the right leg. It doesn't hurt to touch or rub the thigh nor when I raise my leg. There is no pain sitting or laying down. Fortunately I have a walker and am able to walk with it as long as I don't bear weight.