bumps on testicles

i'm in my late 20's and i'm more concerned now about these bumps i have on my testicles. they don't hurt, itch, or irritate me. the thing is one day, i was a scratchin, and nicked one of them. it grew larger in size no bigger than the size of a pea. so i did what human nature would tell you to do, i looked and squeezed it. it popped and a thick, off-white, gluey like substance came out. almost like poppin a pimple. well the bump disappeared and what was left was like a cut. it scabbed as would any cut and it healed with no issues. the thing is there are other bumps not as big as the last. WHAT ARE THEY ? weirded out. by the way i've had them since puberty and i've been checked for STD's (negative results) and the equipment works. HELP.