I had this when I was pregnant, too. I found that putting my legs on a pillow helped, (elevating them). I think it has something to do with circulation.
That could be the case. At the time I was developing toxcima and swelling like a pig. The RLS could have been
related. I never mentioned the RLS to my doctor because there was so much going on and I never related the two. Remember, it was 31 years ago and all this was so new.
I hope you got relief.