what is this pain?

Hi, I posted earlier about leg pain that id had in the night. Its come back about half an hour ago. What is it? Its like a pain in lower leg and thigh that comes and goes like someone pressing an on/off switch. I’m more worried cos its in my good leg…does this mean that this is now going to be effected? I’m getting lil worriednow that both sides are deteriorating :frowning: x