Does he ,like all little boys grab at it maybe he did something that caused it to bruise, keep an eye on what he does if he has formed any habit of fiercely grasping it .Does he climb around a lot , that he may have fallen are you his only care giver ?..
no he isnt potty trained yet and i have been using the same laundry soaps, bath soap, and diaper cream. It went away but it still worries me....
I would say this may be an allergic rash, possibly diaper or creams, maybe even bathing gel .could also be chafing is he potty trained yet ?