Evangeline Lilly surprised everyone at the "Ant-Man" premiere by revealing that she's seven months pregnant! On Monday night in Los Angeles, the 35-year-old "Lost" actress debuted her beautiful baby bump for the first time on the red carpet, and even though it was pretty obvious, she officially confirmed it for E! News.

Lilly is due in September and this will be her second child with her partner Norman Kali, who was a production assistant that she met on the set of "Lost."

 "This is my second time around," she explained. "And I find I've been pretty lucky. It's pretty straightforward, and I just love it. I feel good, I feel blissful."

The star stunned in a black and white one-shoulder gown and couldn't be happier about how the pregnancy is going so far.

"It's so great. I feel wonderful," she told People. "I have to say, high heels and doing a red carpet is starting to ache."

Her son Kahekili is four now, and even though this is her second time around, she's experiencing a lot of new things.

"My first one, I was 30, now I'm 35," she continued to say. "I'm much more tired this time. The last time I was off work, I had no children, I had a partner who was busy working 18 hours a day, so I had all day to meditate and love on my baby and just be pregnant. This time, I have a 4 year old I'm running around after, I'm working full time and I have a stay-at-home daddy so he's always around...I just haven't had the same kind of time to give this my attention."

Once the red carpet was over, and the news was clearly out, she posted a baby-bump photo to her Instagram backstage at "Conan" later that night.

She was truly glowing in a yellow dress with her hand on her growing belly. "Backstage @conanobrien! @teamcoco @antman @marvel #antmanpremiere," the caption read.

Catch Lilly in Marvel's "Ant-Man" when it hits theaters Friday July 17.

 Backstage @conanobrien! @teamcoco @antman @marvel #antmanpremiere

A photo posted by Evangeline Lilly (@evangelinelillyofficial) on Jun 29, 2015 at 4:33pm PDT