Should I Be Worried Of Bump On Tip Of Penis?

small white almost pimple like bump on the tip of penis, isn't popping or anything like that, slight burn when I pee I think I have had this in the same area before and it just went away. I took several std test a few months bad all negative but i didn't take a herpes test, is that something i should be worried about , it doesn't seem like a cold sore but of course im no doctor.