Lindsay Lohan MISCARRIAGE -- I WAS PREGNANT ... During My Reality Show

Lindsay Lohan says she suffered a miscarriage during the taping of her reality show.

Lohan dropped the bombshell during the final episode of the OWN show Sunday night ... when asked to reflect on her experience with the reality show.

"No one knows this," Lohan said ... "I had a miscarriage for those two weeks that I took off.”

She continued, "It's a very long story, but that's why on the show when it says she doesn't want to come down, I couldn't move, I was sick. Mentally, that messes with you."