Brake/clutch fluid is usually a clear straw-colored liquid and it definitely does not feel like water. You could buy a small bottle for a dollar or two at an auto parts store and see if you think that is it. If so, I would take it to the mechanic fairly quickly to find the leak because (a) you don't want to lose even partial brake function and (b) the stuff eats up paint like there's no tomorrow, so the shorter time it's leaking over your painted body metal, the better.