Natalie Portman is Pregnant, Expecting Third Child at 44 Years Old

Natalie Portman just dropped a big baby bomb ... she's expecting her third child!

The 44-year-old made the reveal in a new Harper's Bazaar interview that was published on Friday, saying she's "awed" and "excited" to be pregnant again.

This will be the acclaimed actress's first child with partner Tanguy Destable ... and she tells the mag she's "grateful" for the pregnancy, calling it "a privilege and a miracle."

The actress was snapped out and about in Paris Friday amid the exciting announcement ... covering up any signs of a baby bump with a green coat.

Natalie says that -- because her father is a fertility expert -- she "grew up hearing about how hard it is to get pregnant."

And she's not taking it for granted, adding ... "I have so many people I love who’ve had such a hard time with it that I want to be respectful around that as well."

Emotionally, Natalie's full of gratitude ... and physically, she's thriving. She tells HB that she has "more energy than I thought I might" and has been swimming and doing gyrotonics workouts to "keep strong" during her pregnancy.

She joked about being preggo in Paris, telling the publication ... "In France, they consider full-term to be 41 weeks rather than 40, so I guess I get an extra week to be pregnant this time around."

Since this isn't Natalie's first rodeo, she feels confident about welcoming her new child with her music producer partner, saying ... "We’re going to make lots of mistakes, no matter how hard we try. And also, we’re going to do a lot right without having to do research."

As far as pregnancy cravings ... she tells the mag that she has a hankering for pineapple and melon.

NP shares her first two kids -- her 14-year-old son Aleph and 9-year-old daughter Amalia -- with ex-husband Benjamin Millepied, and tells the mag she's been spending a ton of time with them lately ... which she says is "always the best."