I don't think it's your waterbag. I pee also water gush out like waterfall cos cannot tahan. Even if you sneeze, it will be urine that comes out because being pregnant our bladder kena pressed by our growing baby. But if it is true or if you think its tour waterbag then you must go to A&E asap because waterbag burst at 12 wks is very risky for your baby
I think its urine...i also the same if i sneeze or cough sometimes i have urine leaking. Thats y i use thick panty liner