What Could The Swelling And Pain From A Circular Blue And Red Mark On My Skin Be?

While i was walkin sth hit me I am not sure if is just a stone or a bite from sth else. It formed a circle of blue and red and the middle is my skin color and it swelling. It hurts if a press on it or touch it. Someone also suggested it could be from electricity as i touched it while walking by accidently it made you know like little electricity and also while jumping off the sidewalk it caused the same. Appreciate your help