Most likely those are yeast rafts... Little white bits fairly small? if you look at them, they look like they really are more little clumps of even smaller white spots? The yeast can do that some times.
What to do? nothing wait till you bottle. If they are still there, you probably will want to avoid bottling them, harmful? no, but most like clean looking beer.
Oh and taste youre beer when you test the gravity (or rack or bottle) to have an idea how it is going. It should taste beer like, although warm and flat.