There are a few reasons behind your steady stream. For one thing, the hormone hCG triggers an increase in blood flow to the pelvic area, causing you to make more pee. In addition, the efficiency of the kidneys improves during pregnancy, so your body gets rid of waste products (i.e. pee) more quickly. And let's not forget your growing uterus, which puts increasing pressure on your bladder as it gets bigger. (And bigger!)
The good news is, this pressure lifts once the uterus rises into your abdominal cavity in the second trimester. Until then, be sure to lean forward when you pee to completely empty your bladder, which might cut back on trips to the WC. But don’t stop downing the liquids — your body needs them.