37 w 5 d, feet swelling

I’m 37 weeks 5 days today. I’ve had some mild swelling in my hands and feet but yesterday my feet ballooned up. I’ve been keeping an eye on my BP (it’s high but not dangerously high). Last week I had some labs done because I was lightheaded and found out my sodium levels were low so my OB instructed me to drink more Gatorade. I have an appointment this afternoon - just a little concerned to see the swelling happen so soon. This was after work but I have a desk job and keep my feel propped on a box under my desk.