Sitting all day at work made mine worse honestly. I started walking a bit every hour, elevating feet during breaks and wearing comfy chappals. Avoid too much salty food also, helped me.
Keep ur feet up whenever u sit, dont stand too long, and stay hydrated. I used to put a pillow under my legs at night. Some swelling is normal in later months though.
Mild swelling in legs is common, but I'll add this, if the swelling is sudden, on the face/hands too, or with headache or blurry vision, please call ur gynac immediately. I was told to watch for that.
Leg elevation, lots of water, light walking and not sitting cross legged helped me. Cool feet soak felt nice too. But sudden or heavy swelling, get it checked, dont ignore.