Swelling

So I'll be 37 weeks tomorrow and the last 2 days I've had a ton of swelling in my legs, ankles, and feet. It's not just swelling though, my legs feel twitchy and restless. I try to elevate them and it makes them worse. I've also been having times where my heart feels like its racing and it's hard to breathe. I have an OB appointment today and will bring it up but I never experienced this with my first and was wondering if it's normal?