I have had a small red itchy bump that pops up than leaves after a while. they keep doing the same thing in different spots. what is happening? why?

My first thought: is that those could be hives, also known as urticaria, which is very common. It can be triggered by many substances or situations: some foods (especially nuts, eggs, shellfish), insect stings or bites, pressure, heat, cold, exercise, infections, pets, pollen, some plants, etc. You see...very common! Try to identify triggers to avoid; for more help, see allergist. Good wishes:)