, or as its medically known: an ecchymosis, is a very common occurrence. We all experience these from time to time. If this symptom is continuing longer than normal or is more severe than normal, I would recommend that you see your primary care doctor
To answer your question, YES -- it is very possible to have a bruise or ecchymosis without any skin discoloration. A bruise is essentially a traumatic injury
to the muscles and soft tissue an area. This results in damage to the small blood vessels resulting in a small amount of blood leaking out into the soft tissue. Most of the time the trauma causes damage just to the soft tissue under the skin (as the injury normal occurs from the skin). Therefore, the blood is visible under the skin and therefore we see the classic bruise. Sometimes however, the blood is not visible under the skin -- either because the damage is deeper or the skin just is thicker in that area. Regardless, it is possible -- although certainly less common than the classic bruise.
That being said, there are other things that could be causing your symptoms. If these do not resolve soon or are different than normal bruises -- please see your doctor to have this evaluated. Good luck!