It's quite common to get that with cheap earrings and would think it's the most likely reason, you are reacting to the cheap metals. when I had mine done years ago, it was advised that you wear a permanent stud or ring from 9ct gold or silver until the hole completely heals. It used to be 6 weeks, probably different now. as well as saline I'd advise rinsing with diluted dettol/savlon or cream as well. if you can bear it see if you can get some gold/silver sleepers in now rather than having another hole punching!