Some beers make little to no krausen, or it falls quickly. Others make giant, ugly krausens. It depends on the recipe and the yeast.
Bubbling is a good sign that you have fermentation (though lack of bubbling does not mean that you don't).
Leave it alone. The yeast know how to make beer; let them. Wait two weeks, then take a hydrometer reading. Wait two days and take another. If they match, you are ready to rack to secondary or bottling bucket.