Very strange bumps on front part of right shoulder...

Shortly after my shower, I was applying coconut oil to my right arm. I was looking in the mirror and I noticed these raised bumps on the front of my shoulder. I stared at them in amazement...they looked and felt like little tumors (about 10 of them) and they were very sore. I continued to message them cuz they were sore and they disappeared into my muscle I guess. I have thin arms and have never seen anything like that ever. It looked like various sized marbles. Does anyone have any explaination?? Im totally spooked! Tweet