What Causes Painful White Dots On Penis Head?

Hello, I have a question. A few days ago I was at work and at the Ed of the day I felt the tip of my penis feeling very tender. When igot back home I pulled my foreskin back and saw there was little white dots on the tip of my penis and they hurt very bad. I thought it was my work pants making my forskin chafe the head of my penis. I'm worried it could be something serious because the pain or the white dots hasn't gone away yet. But the thing is I haven't been sexually active with anybody in any way in the past 5 months so I was wondering if there was still a chance it could be STD?