question about lump on babys back

Sandra

so when our son was born I don't remember feeling a bump on his shoulder of course I had been through alot of pushing so looking for lumps was not on my to do list well the nurses day 2 took him away for shots and a check up and when he came back I noticed the lump I tried a ski g about it but they blew me off so the day we brought him home he went to the pediatrician the next day he felt it and said I THINK it's a hemo birth mark it will get bigger (THINK was not the word I wanted to hear I wanted I KNOW) so anyways his one month appointment came and now the other Dr can't even find the lump its so small so was it a hemo or did a nurse hurt my son and its healing? ps when we brought him home he would roll to his side and not want to sleep on the lump