I have 2 clusters of very tiny bumps on both arms and a few scattered on the arms as well but not far from each other. They don t itch and are just like my skin colour. They re difficult to sight and you d have to look closer or at a certain angel to actually see them. I noticed them after a morning shower about a 2weeks ago. They haven t spread and look just the same as the beginning. They look harmless. What might they be and should I be worried??