My son is touching himself ...!

Hello, my son is 2 years old, when I gave a birth him I decided to him have “circumcision” So, I have noticed that he always is touching his penis, he take off his diaper and run naked and also, touching himself. He just do it here at home, he never tried to do it in public. I’m still teaching him to go to there bathroom, so I don’t know if that have something with it. I tried to tell him that’s not right but he’s still doing it. I don’t know what to do, is that normal in his age? Should I take him to his doctor? Please, don’t rude comments.