Chrissy Teigen says she actually didn't have a miscarriage in 2020 like she said ... she now says she actually had an abortion, but didn't realize that's what she did until recently.

Chrissy spoke Thursday at a summit called "A day of Unreasonable Conversation" ... saying it wasn't until nearly a year later did she process the fact that she had an abortion.

She said, "Two years ago, when I was pregnant with Jack, John and my third child, I had to make a lot of difficult and heartbreaking decisions. It became very clear around halfway through that he would not survive, and that I wouldn’t either without any medical intervention."

Chrissy and husband John Legend announced they lost their son Jack at 20 weeks due to pregnancy complications ... calling it a miscarriage.

But, now she's backtracking all that ... "let's just call it what it was: It was an abortion. An abortion to save my life for a baby that had absolutely no chance."

Although she wasn't specific, it seems what she's saying is that doctors advised her at around 20 weeks the baby would not survive and she would probably die as well if she carried the baby to term. So, it sounds like doctors may have induced birth, knowing the baby would not survive, which she characterized as a miscarriage.

Chrissy went on to say the decision by the Supreme Court to overturn Roe v. Wade triggered the realization.

"I fell silent, feeling weird that I hadn't made sense of it that way," Teigen shared. "I told the world we had a miscarriage, the world agreed we had a miscarriage ... and I became really frustrated that I didn't, in the first place, say what it was, and I felt silly that it had taken me over a year to actually understand that we had had an abortion."

Chrissy and JL have 2 kids together -- Luna and Miles. The couple announced they are expecting another baby saying ... "joy has filled our home and hearts again."