Hello guys I have a concern in which I'm going to get tested on Monday but just need some inputs. On my penis I have a red spot which seems to come and go. I have looked at pics of syphills and it looks nothing like that . It's not like a open wound just a red spot that comes and goes. It's been there for about a month and half any input could this be a std. I received breif oral sex almost 2 months ago in which I stopped it last like 5 seconds.does syphilkis behave in this behavior?