2003 Chev Trailblazer LTZ EXT 4wd - no oil showing on oil dipstick.

I am stumped and worried. I have a 2003 Chev Trailblazer LT EXT 4wd that runs great
(at the moment).  I was checking the fluid levels as a normal routine and did not see ANY
oil showing in the oil dipstick. This wasn't a big concern at the time.  I added a quart of oil
and checked the level. Still nothing showed.  Now i was getting concerned, so i added
and checked again and again.  Now i have put in 8 (yes, eight) quarts of oil and still,
NOTHING showing on the dipstick.  I had a couple other guys check it and check for
leaks and there is no oil on the stick and no oil leaking on the motor or under.  No leaks
found anywhere and there is no heavy exhaust smoke.  Sooo... I am concerned that i
have too much oil in the motor now, and how dangerous that could be.  Also, i am
stumped on why there is no oil showing on the dipstick.  If the dipstick tube was
disconnected from the oil pan, i would assume i would have an oil leak from that area,
but i don't. My oil pressure gauge show 40 now as it did before i added the 8 quarts. Any
idea why there is no oil showing; also how i can resolve the issue; and how dangerous it
is to drive around with too much oil in the motor -- even if the dipstick shows no oil and
the pressure gauge shows normal pressure.