Could this bump on my ear be a keloid from my piercings?

Yes: Mostlikely, it is a keloid and can be safely ignored unless it's painul or growing.

Yes: Yes it could be, especially if you belong to a non-white race group. Keloids are far more common in darker skinned races, the darker, the higher the risk of it being a keloid. You can get silicone coated pressure stud earrings to reduce them, do not cut out, will grow larger! see my answers on treatment in this site.