There's a few locations for typical leaks. The best way I know to find them to clean up the bike and remove the skid plate (if it has one). Then dust the crankcase with baby powder or flour, something white that will soak up the oil and point you to the source of the leak(s).
The pop may have come from the exhaust... unburned fuel building up from sitting and idling. That's really nothing to be concerned with, if that's what it was.
This shall pass, be still and know.
2006 XT225, UNI filter, ProTaper bars, MSR handguards, SS front brake line, Shinko 241's.