I think it is nothing at all, but you can see a Dr. You will need to overcome your fear of being called sexually active because many things attack our body on a daily basis and sometimes they atack our gential areas and need to be looked at.
All you can do is reassure your mother that you are not having sex and if she trusts you then she will believe you.
hi...honestly it could just be an ingrown hair ecspecially if you shave.