[V6-12v] Oil Light

[Nathan Widmyer]

My dad and I went to change my oil the other day.  Like last time,
this time it took nothing short of a herculean effort to get it loose.
 I thought the oil pan was going to fall off.  Well, the oil drain
plug came off and the oil was changed and replaced the oil drain plug
(mutilated beyond the point that a proper-sized wrench cannot fit it).
 I went to go somewhere today and the Oil light started flashing for
about a half of a mile.  I pulled over and looked underneath and saw
no oil dripping from anywhere, the oil drain plug didn't back out.  I
started it back up and the oil light didn't come on once.  Now, before
the oil was changed, I could start the car and the oil light would
flash maybe 4 or 5 times then stay off and I thought that was because
I put too much oil in and it made a censor go haywire.  I'll look at
the place my car is parked and see if any oil is on the ground
tomorrow when it's light but I don't expect any.  If I get this much
trouble changing oil, I'd save much trouble and just get a Fumoto
valve.  What did I do wrong here?  (sorry if this isn't in an easily
readable format)  Thanks, Nate.