I have left arm pain with numbness and tingling in my left pinky finger.

From your elbow...: Is the pain in your entire arm or just below the elbow? This could be coming from inflammation/ irritation of your ulnar nerve, mahybe from medial epicondylitis (or other causes). Have you had an elbow injury recently, or do you do a lot of repetitive motion involving your elbow? It is also possible for these symptoms to be coming from your shoulder or neck.

Agree: Agree that numbness and tingling in the pinky finger is likely a pinched nerve in the neck (c8) or injury to the ulnar nerve. Would suggest a physiatric or neurologic evaluation. May benefit from emg/ncv testing.