Hi there. Great job working out!! That's so important and especially if you are anywhere that is currently on pause due tot he corona virus. BUT, pull ups are often associated with elbow pain. I'd discontinue that particular exercise. Pull ups will stress your elbows AND wrists. I would ice the elbow and try ibuprofen if you can take that for any inflammation. Go easy on other exercises until the pain is better. But in general, that may not be the exercise for you. (pull ups). Are you doing cross fit?
If you are doing exercise in a wrong form then it will lead to injury. You should stop doing exercise for some days and take complete rest. If the elbow pain increases without doing exercise then you should consult your doctor.
Hello~Ease up on the exercises that are causing the pain, and if it continues, then it is probably a good idea to contact your GP.
That area of the elbow is the olecranon bursa. Inflammation/swelling of this region is called olecranon bursitis.