"Twilight" actress Kristen Stewart has reportedly gained weight which is making her look much heavier than her usual petite self. And this weight gain has instigated pregnancy rumours. Fans are wondering if Kristen Stewart is actually pregnant with her former co-star and on-and-off boyfriend Robert Pattinson's baby. Meanwhile, rumours about Robert Pattinson and Katy Perry’s alleged hook-up are swirling around. Read on to find out the truth.

Looking at Kristen Stewart's stills from the set of her upcoming film "Still Alice," the Hollywood actress seemed to have gained significant amount of weight, reported Hollywood Life. According to the report, the actress has put on some 15 lbs, and she now appears to weigh 125 to 130 lbs.

Kristen Stewart's recent weight gain has aroused a frenzy of speculation, sparking rumours that she could possibly be pregnant with Robert Pattinson's baby. But these rumours seem to be just a hoax making the rounds. Debunking the fake rumours, a friend of Kristen Stewart revealed the truth about her recent weight gain and pregnancy rumours.

"Kristen is absolutely not pregnant," a friend of Kristen Stewart told Hollywood Life.

"She has put on a few extra pounds for a movie role and that's it. She's already so thin so a few more pounds makes a noticeable difference, she's still thin," explained the friend.

According to the insider, her "priority" is her career at the moment. Though the insider reveals she "would love to be a mom one day and have little rugrats running around, but not for a while."

Kristen Stewart broke up with Robert Pattinson in 2012 after the actress' cheating scandal with director Rupert Sanders came to light. They began dating each other when the former couple was filming their box office hit movie franchise "Twilight Saga."

Pregnant or not, Kristen Stewart is reportedly looking "healthy, happy" and curvier after gaining a few pounds as noted by Lisa DeFazio. DeFazio is a celebrity nutritionist and registered dietician. Besides KStew's pregnancy rumours, more reports claim that she wants to celebrate her 24th birthday with her ex-beau Robert Pattinson. And if RPatz attends KStew's birthday party that would be the "ultimate birthday gift for her," reports Hollywood Life.

Meanwhile, rumours claim that Robert Pattinson and Katy Perry "have taken their friendship to the next level." According to The Stir, the two "have never stopped being in touch" with each other. They have been in touch through texts which "stepped up in January" after Katy Perry's alleged break up with singer John Mayer. Their texts have reportedly "hotted up." The report claims that Robert Pattinson and Katy Perry are "just friends -- with benefits -- at the moment." Rumours about RPatz and Katy Perry's alleged romance are making the rounds, but there is no confirmation yet.

It is reported though neither Robert Pattinson and Kristen Stewart are dating (Hollywood Life). But do you think the "Twilight" co-stars and former couple, Robert Pattinson and Kristen Stewart, will come together on the special occasion of the latter's birthday?And what do you think about Kristen Stewart's recent weight gain?

For more news on 'Twilight' actors Robert Pattinson and Kristen Stewart, read below:

Robert Pattinson, Kristen Stewart 'Still Crazy About Each Other': KStew Sends Cute Selfies to RPatz in Return of Valentine's Day Flowers-Report

Attention Robert Pattinson! Rupert Sanders Still in Love with Kristen Stewart, Hopes for a Future with Her?

Robert Pattinson and Kristen Stewart Failed Reunion on New Year's Eve, Actor Instead Spotted on Dinner Date With Mystery Girl