I take 20 mg amytirtaline at night for nerve pain in both my thighs I find on going to bed I am getting jerking movements in my legs is this Normal?

Yes. It is most probably a physiological response and not important. The dose of Amytriptiline is small and not likely to cause major side effects. But why are you getting "nerve pain" in your thighs? Have it seen to if it continues.