21 weeks 5 days pregnant with a purple line on each ankle

Last OB appointment she said my BP was ok, and I had just noticed a couple days before my appointment that I had a single purple line on each ankle. She suggested I elevate my feet more. I have been trying when I go to bed for a week or so now and after not wearing socks for an entire day I've noticed they've come back. The purple went down a bit as I wasn't doing much but last night I was on my feet for a good two hrs in oofos flip flops because that's all I had since it got hot until I bought new shoes yesterday. I'm just concerned if I should call my OB about this in the morning or if it's just fluid retention or maybe something to be more concerned about. My hands have been a little more swollen lately and my calves feel a little more uncomfortable from time to time.