Does A Big Bump On Head That Oozes Yellow Pus Be Cancerous ?

My husband have a big bump on his head and it comes out it different location on the head. Sometime when you squeeze it yellow puss comes out. He went to the doctor n they said its an infection and they gave him antibiotic and it left but a really bigger one came back....he pops it flat but then a few hour later it's big again...it's like when u pop a pimple n it come back but way bigger. Can it be the clippers he cut his hair with because I cut my brothers hair and it was full of pop pimples and dry skin, but I cleaned it...but after I cut his hair my husband started getting these things. what can this be we scare it's cancer or something