Jennifer Lopez says she wasn’t worried that she wasn’t able to get pregnant quickly.

“We knew nothing was wrong with either one of us — I had been checked, and [my husband Marc Anthony] had kids already,” she tells the October issue of Elle. “I knew something’s not ready here, in my head or in my life, and when it is, I know it’s going to happen.”

But she says she knew instantly when she was pregnant one day while sitting down for hair and makeup.

“I felt a flutter. The weirdest little … flourish,” she recalls. “My makeup artist said, ‘What’s the matter?’ I didn’t say anything, but in my head, I was like, ‘I have life inside me!’”

Following weeks of speculation, she announced she was expecting during a Miami stop on her El Cantante Tour concert in November 2007.

“While pregnant, we came off tour and I said [to Anthony], ‘I did the superwoman thing, I finished the tour — now I need you to take care of me. I love doing things for you; if I’m not cooking, then I’m picking out a shirt.’

“‘But this is the first time in my life where I’m just going to be a little bit selfish. I don’t know if I’m going to have kids again, so I want it to be a beautiful experience. I don’t want to have any drama. I want to just be smiling every day.’”

To remember her pregnancy with twins Max and Emme, she commissioned a book of photos of herself for Anthony two weeks before giving birth.

“I was like, ‘How am I going to rock this moment of my life?’” Lopez says. “I felt very womanly. Marc was in a dream. He loved it.”