I Got A Tattoo On 12/31/16 And It Healed Really

I got a tattoo on 12/31/16 and it healed really well however I got this bump and it filled with pus and I squeezed it out and cleaned it but it kept coming back and it is really red and warm to the touch and it feels hard like the head is still in there. I put antibiotic cream and band aid on it but it still filling with pus. what could it be