Melanoma , rough slightly raised red spot

Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by slightly raised red spot on chest below the rib cage about 0.5 cm in size. You have also made a mention of melanoma in your father.
It is very difficult to comment online and the image that you sent is also not available to me. The possibilities could include a harmless de Morgan spot which is a small hemangioma and a sign of aging of skin usually seen after the age of 40 but can occur earlier as well. The other things to rule out are acne or skin spots due to some blood malignancies. You can see if this skin lesion remains so or it undergoes any change in size, color or appearance over time when it might be the sign of alarm and you must consult your dermatologist urgently for definitive diagnosis and to rule out malignancy as the same is not possible online.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.