I just dealt with this same problem. It is very annoying and I found it a bit concerning since it appeared all of a sudden too. Based on my midwifery education (student) and my midwife's advice, this is what I did and it worked - I increased my protein intake by about 25-30grams a day (I added an egg to my breakfast, cheese and crackers mid-morning and made sure to eat a handful of almonds in the afternoon in addition to my usual 3 meals a day). I also try to be mindful of salting my food to taste and I find yoga really helps too. Within 4-5 days, my feet and legs were pretty much back to normal. I have been eating well all through my pregnancy but there was a week when I was on vacation from work and not in my usual routine...think I wasn't eating as much and my body let me know.
you can google blue ribbon baby, Dr Tom Brewer or Brewer diet for information about the connection between diet and swelling/protein in urine/high blood pressure. I can't imagine following their diet advice to a tee - that is a lot of food! I just go with the principles of it all. I agree that it's wise to call your health care practitioner so they can make sure nothing serious is brewing.
I really hope it settles for you soon
married to DH, mother to two amazing little boys born May 18/2010 and May 20/2013!
Infertility has been part of this journey - no more littles for us, but so grateful we have two happy healthy boys and we can now begin to heal from that experience