Wake up with numness in my whole side when I sleep on my side. It's worse on my right side.?

I'm 20 weeks pregnant today and When I've been waking up for the past week my whole side hurts and is numb. It's numb all the way down almost to my knee and is numb all the way up to my ribs. it also really hurts right around the area that my under wear hit. My underwear are not snug and I even switched to a looser size trying to see if that would help but it didn't. It is uncomfortable to sleep on my belly or my back, so my side is my only option and it's horrible. Is this normal? I didn't have it in my first pregnancy. It's worse when I lay on my right side. Thanks!