Despite the best efforts to find a reputable shop or person to pierce your ears or other body parts, there are some people that will experience side effects. The hope, of course, is that these are not anything more serious than a minor annoyance, but there is always a small risk of other things, some of which can be serious. Yours does not sound like a serious issue, but there are several things that it could be, although it is impossible to say for sure without seeing it in person.
One of the likely possibilities includes a hypertrophic scar, which is different from a keloid because keloids grow and hypertrophic scars gradually get smaller over a long period of time. Both of these are variations on normal skin remodeling following an injury
, and both of these are more likely to occur in the teens to 20s age groups. There are treatments available if it is either of these. Another option would possibly be some sort of infection, perhaps involving either the skin or the cartilage. The absence of tenderness makes an infection less likely, however. Please discuss your ear with your doctor
, who will be able to look at it and make the appropriate recommendations.