Check your oil filter gasket - the gasket between the oil filter and the engine block. PITA to replace - $600 worth of labor to replace a $15 gasket
I didn't know mine was leaking either until I took off the splash guard to change my diff fluids. Never saw a drop on my garage floor, but it was loosing about 3/4 of a quart between oil change. Just thought the X was beginning to burn oil (never burned a drop previously). But apparently, it was weeping onto the splash guard.