I meant you have to keep doing this. Not just once.
Get a lemon and squeeze the juice in your water. Drink this around the clock. You will be frequenting the restroom a lot but the fluid will drop off significantly. It helps reduce your sodium intake. I retain sodium whether prego or not and it works! But you got to attack with it.
Ash is right. Try to keep your feet elevated when you can and make sure you are drinking lots of water. The only other thing I can think of is to make sure you cut back on your sodium intake (if that's an issue). Salt can make you retain water.
This is also the time you should be asking your significant other for foot/ankle rubs. Better yet, go get a pedicure and spoil yourself. Win win!
I'm in the same boat 36 weeks and 5 days and I've been drinking lots of water and elevating my feet when I get a chance. Its helping a lot more, I can see my ankles now haha.