Don't really worry about pushing too hard, it's even ok if you were to break a rib or two. it's better to push too hard than not hard enough
I would go with the last choice
rest, ice, compress, elevate, stabilize
Red blood cell antibodies may show up in your blood if you are exposed to red blood cells other than your own. Antibody serology tests check for the presence or level of specific antibodies in the blood.
