White Bump On Penis, just beneath the head..

i'm 25 and lost my virginity just about last year, as a teenager
i was unaware about proper genital hygiene and did masturbate frequently.
i've hardly had 3-4 sexual encounters, last one was almost 6 months ago
and at all times i had protected sex..some friend advised me on proper
penis hygiene because it used to become very itchy and some sphygma also
used to get accumulated, so i started cleaning it regulary with my hands and
water while bathing.just about 15 days ago i noticed a white colored
bump of a small size just beneath the head of my penis on the shaft, i have to
retract my foreskin to be able to see it. i got worried and searched the
net to check for this symptom. this bump i have is painless, but it has
grown a little bit.i have very less knowledge on this,like if it's a wart or something harmless, but i believe it is not a fordyce spot coz i have many of those around my shaft and around the base,they are hardly visible and are not that bumpy. I have noticed a similar bump (in question) again just beneath the head of my penis, and am worried again coz i think its spreading, please advice on what should i do..