If you had muscle damage, the capillaries burst and bled into the surrounding tissue, which is bruising. The damaged tissue bleeds longer because of coumadin and the bruise gets bigger and uglier. The deed is done. Stopping the coumadin after the fact won't fix anything. That's closing the barn door after the horse got out.
Can you stop taking it? Yes, then your INR returns to whatever it would be naturally. Then you are taking a risk because with normal clotting time tiny eddy currents around the artificial valve can hold blood in a whirl until it clots. Then when the clot gets flung out into the blood stream it can lodge in some small blood vessel. Now, that could lodge in the left big toe or the elbow and you would never know it, but what if it clogs a capillary in the brain? Sudden stroke, that's what.