What Causes Lumps On The Shaft Of Penis Post Unprotected Sex?

I had unprotected sex about 2 months ago about twice and once again about 4 weeks ago only this time with a different person. I have been examinating closely to look for any chance that I might have caught an std or something of the sort. I m not 100% sure that they weren t there before but I found two bumps on the underside of my penis. Both appearing to be the exact same just different size, one is towards the middle of the shaft and the other towards the top. They appear to be molluscum contagiosums atleast I think, they don t not hurt or itch at all they only get sensitive if the top layer of skin is removed from one. The two bumps are no bigger than the tip of a pen in size and around one of he bumps a cluster seems to be forming it s just not very visible yet. They have almost a rough like texture and look to be sitting ontop of the skin not in it.