Dark Clock

hi everybody i need some help, as long as i can remember i have had
these (multiple) white heads on my shaft (but they stop before they
reach the head) and i usually can pop some of them, some of them i
can't and when i can looks like white puss comes out, and im scared
that this might be some sort of STD, and i was wondering does
anybody know what this is? is it normal? do alot of guys have it? if
someone could help me please! that would be great.


thanks