What Causes A Painless Bump On My Penis?

I have a bump that appears to be a spider bite or pimple about 2 inches above my penis. It is not blistering, nor does it have the "head" of a zit. It is tender, but doesn't sting, burn, or itch. The bump is probably a quarter inch wide and firm.

It appeared a few days ago, maybe 3 or 4. Maybe getting smaller?

Could it be herpes? I was exposed to the blood of someone with herpes when she cut herself and I was dressing the wound. Got her blood on my hands.

Thanks!