I have a 1 1/2" bean shaped lump on my right shin under the skin, it is 4" below the knee to the left of my shin bone. its movable and not painful.

From your limited: description, it sounds like a lipoma or fibrolipoma. I cannot be sure without actual exam, so show it to your doctor just to be sure.

Varies: There are a number of possibilities from a bursa to a sebaceous cyst, lipoma, lymph node, etc. hard really to say more without actually seeing it. Consider being seen for an accurate diagnosis.