One difference you will notice in your habits is that you will want to urinate more often. This is because the uterus which holds your fetus is expanding and putting pressure on the bladder. This pressure feels similar to having a full bladder. Like nausea, this condition should clear up in a few weeks, but it may also come back at the end of pregnancy when a much larger fetus is being carried in the lower abdomen and again exerting pressure.
Despite this condition, it is important to keep drinking plenty of liquids. Clinicians recommend a minimum of two quarts of liquid a day. Remember that your growing fetus needs these liquids. You can however prevent walking up in the middle of the night to urinate by avoiding liquids a couple of hours before going to sleep.
Another common problem which may occur is urine leakage when you cough, laugh or sneeze. This is called stress urinary incontinence. As the uterus grows it puts pressure on the bladder. In addition, the relaxation of the pelvic floor muscles compounds the problem particularly during second and third trimesters. Kegel exercises will help strengthen the pelvic floor muscles. If the urine leakage continues after delivery, continue with the Kegel exercises.