There is a pea sized bulge in the radial artery or vein in my right wrist. it's rather hard and can be moved around to some degree. it's blue.

May be phlebolith: If you are sure it is on radial vessels , most likely you have blood drawn at the site , some times small clot organizes and feels what you are describing and harm less show to your doctor to make sure it is not something else.

Visit doctor: It could be a number of things so a physical exam and ultrasound of the bump would be a good idea.