What Causes Small Bumps On The Shaft Of Penis?

hi im a male that had unprotected sex about 4 months ago that around the end of november and now i see like little dot or you can say bumps that are red but they look like they under the skin. and if i sqeeze my shaft and look really close i see these bumps every where. but these bump look the same but they just red around and they do itch alittle but dont busted with puss or anything.i notice it a couple days ago and now they still didnt go away. they are right below my head where my shaft starts.