Aiyoh, that's actually quite normal lah, at 32 weeks your body is doing a lot of fluid shifts and sometimes you lose a bit of water weight while baby keeps growing steadily, which is the important part! A few of us mums experienced the same thing, weight fluctuating week to week but baby's growth on track, and our doctors said not to worry as long as baby's measurements are good. Since you're already being monitored, just mention it to your gynae at your next checkup so they can make sure everything is balanced, but honestly sounds like baby is doing beautifully!