pregnant belly

Natalie Portman is one active mommy-to-be!

The gorgeous Black Swan actress went for a hike near the Hollywood sign to stay in shape for the Oscars ... which is just weeks away. Portman, 29, is nominated for Best Actress, and we have a feeling she'll win!

The actress says she is due this summer, although many believe due to the size of her growing bump, the baby will be coming sooner. No doubt, Nat and fiance Benjamin Millepied are counting down the days.

Ms. Portman definitely has that pregnancy glow, or maybe that's just sweat. Either way, she's a beauty!

See Natalie go topless for an incredibly stunning Miss Dior perfume ad after the jump ...