Either could be correct but neither are common sentences with an obvious meaning! Are you talking about blood clotting? If your blood does not clot well, then you could say that you have "clotting trouble".
However, it is your blood which clots and not you as a whole person. So in this context, "I have trouble clotting" would be wrong.
If you clot cream for a living, then you could say that "you have trouble clotting". But I don't know if clotted cream producers use the verb "clot" like this.