Jon Jones: I'm Not a Cheater ... 'Don't Write Me Off Just Yet'

Jon Jones says he's NOT A CHEATER -- and says he still believes he can clear his good name.

Of course, Jon was yanked from UFC 200 after he tested positive for 2 banned estrogen blockers -- which are typically used in tandem with certain performance-enhancing drugs to limit side effects.

He has been temporarily suspended from fighting in Nevada -- and a hearing is expected for later this year.

But Monday afternoon, Jon went to Twitter to plead his innocence.

"Don't write me off just yet, I know in my heart that I'm not a cheater," Jones said.

"I trust in the system to help me prove it."