I have a lump on my left shoulder blade, what should I do?

See PCP . 'lumps' on shoulder blades could be several things but what u should do is see your physician. Fatty benign tumors( lipomas) are common here.If u fell, an organizing hematoma may be forming. Osteochondromas are not uncommon on the scapula. All this is speculation; see your pcp w/ possible referral to orthopedist. Best of luck!