Should I be worried and can I get a decay under composite if tiny pieces of food went inside? (Photos)

What are these 3 tiny brown spots under composite bonded tooth? I had my 2 front teeth composite bonded just one week ago. Yesterday I've noticed 3 small tiny brown spots on one of my teeth. What could that be? I must mention that part is where composite and natural tooth separate, it is sharp and when I floss my teeth the floss gets stuck in it. Should I be worried and can I get a decay under composite if tiny pieces of food went inside? Also on another tooth closer to the bottom is one tiny black spot that looks like it is captured inside composite.