Stabbing pain in the upper part of my right arm. along with pain in elbow and occasionally numbness in my pinky finger. what could be causing this?

Radiculopathy: Pain that radiates down the arm can reflect a cervical radiculopathy (shooting pains due to a pinched nerve in the cervical spine). Symptoms going to the small finger would suggest involvement of the C8 nerve. These conditions typically resolve with time and conservative treatment. It would be reasonable to watch it for a week or two, and use NSAIDs if needed, before seeing a physician.

Ulnar neuritis: Sounds like you have irritation of the ulnar nerve. It is very sensitive by the inner posterior aspect of your elbow ….:your funny bone….. If you bumped this area or slept on it wrong it could have caused an irritation. Usually gets better with time, rest, avoiding impact. Get it checked if it does not improve.