My mask protects you, your mask protects me. We know for a fact that asymptomatic and presymptomatic people are still contagious, and at this point we should all assume that we could be carriers. When you have to go places where you come in contact with others (groceries, picking up food, work) consider covering your face if you can. A homemade mask like this one does a lot to contain the droplets of the person wearing it, and the more people wear the masks the safer everyone will be.