Not every pregnant woman has water retention. I had water retention toward my 3rd trimester for my 1st & 2nd kid. But for my 3rd kid, I started to have water retention as early as 2nd trimester. It got so bad that it affected my hand's ligament after I gave birth. Luckily I seek treatment early & recover in 6 months time. My advise to you is drink more water and cut down on your salt & sugar intake. You gynae may ask you to take glucose test to check if you're at risk of becoming pregnancy related diabetic.