Are Red Circle And Warm Sensation To Touch Indicative Of Infection?

I got two tattoos. I got one on the side of my right and the other one was done on my right forearm. I got them done friday night. This is monday obviously. This is my first time getting a tatto. Now the one on my arm has a big red circle and its warm to the touch. Is it infected? If so what can i do to help it?