Aniston, 44, who rocked the Oscars red carpet Sunday night in a red Valentino dress, is reportedly planning a "small affair" for her wedding to Theroux, 41, according to People mag's next cover story.
A source told people that the secretive duo will tie the knot soon, in a small ceremony set to take place after Aniston wraps up filming on an Untitled Elmore Leonard Project in Connecticut March 8.
"Jen seems more confident than ever," the source said.
The couple's appearance on the red carpet also sparked pregnancy rumors -- gossipmongers thought they saw Theroux placed his hand protectively on Aniston's stomach while they posed for photos.
Aniston and Theroux got engaged in August, after the later proposed with a gigantic diamond suspected to be eight-carats in size.