LAMAR ODOM IS NOT IN REHAB

Lamar Odom has NOT checked himself in to rehab oo.. 

There are reports out that Lamar checked himself in ... sources say, he's not there.

Lamar has gone off the radar with the Kardashian family for the last few days.  Khloe -- who has made it clear she will end the marriage if he doesn't get help -- has heard nothing from him.