Hi, I Had A Gastric Band In 2011, My Last

Hi, I had a gastric band in 2011, my last visit was October 2014 & was told there was a fault with the tubing & I would have to pay for it correcting which is not an option at the moment. So about once or twice a month I get pain around the port area & today noticed a blister on the scar, does this mean there is an infection in it?