Jennifer Aniston, who has said that she definitely sees children in her future, is again the subject of pregnancy rumors.

The 44-year-old actress, who has been engaged for nearly a year to actor Justin Theroux, plans to get pregnant by her next birthday, which is Feb. 11, Radar Online reports. “She definitely seemed to have gained some weight,” according to an anonymous source cited by In Touch magazine about the actress on the set of “Squirrels to the Nuts," which is filming in Manhattan.

InTouch magazine teases on its website that new reports claim that Aniston has already started receiving in vitro fertilization treatments, and that the actress has been attempting to hide her stomach with scripts and isn't acting “chipper.”

“She knows the clock is ticking. She’s well aware of it,” the source said. “She’s also done her homework. She’s explored all methods for having a baby and knows what her options are with IVF. She’s educated herself.”

Aniston, who appears on the cover of the September issue of Glamour magazine, touches loosely on the topic of kids in the interview. Aniston also said that she felt maternal toward her 22-year-old costar Emma Roberts in the comedy film “We're the Millers,” which debuted in theaters on Aug. 7. In real life, Aniston said she thinks her fiance, Theroux, 41, would make a great dad. “I know Justin, for instance, has extremely amazing paternal instincts. Because [growing up] he had to sort of become the parent,” she said. “I think when you have to become the parent when you're a younger person, you learn those instincts.”

At a recent promotional event, Aniston told the Associated Press that the couple's wedding plans are still on. “We just want to do it when its perfect and we’re not rushed and no one is rushing from a job or rushing to a job,”Aniston said, adding. “You know, we already feel married.”