Wear a pad to make it easier to monitor what's coming out. It is not unusual for the vaginal discharge to become thinner and more copious as the cervix ripens. However, it might be a small leak of fluid that needs to be managed as ruptured membranes.
You should go in and get checked, not as an emergency, but ring them. (I felt like a real pain ringing them about this as I felt so well, but they want to see you) If it is your waters they'll want to keep a close eye on you for infection if you dont go into labour. It sounds like it could be, not everyone gets masses of fluid. Good luck