I have a small red bump just under my belly button it looks murky inside. It doesn t itch , and it s irritating to say the least. It first appeared after I had unprotected sex with my girlfriend about a few months back (2 at most), and since then it s been there. I honestly don t know what it is, and I m kind of worried its an STD . As well, my family for the last three generations have all died from different forms of Cancer , and I ve heard that this is usually a sign. Is there any way to be sure exactly what it is?