In their new film What to Expect When You’re Expecting,stars Cameron Diaz and Jennifer Lopez take on separate roles of becomingfirst-time mothers. Alongside co-stars Elizabeth Banks, Anna Kendrick andBrooklyn Decker, the ladies grace of cover of the latest issue of Redbookmagazine. Cameron may not have experience just yet when it comes to children,she tells the mag that she had a different plan in mind while growing up!

“I thought I was going to be married and have two children bythe time I was 21. I think I felt l had to model my life after my mother’s,”she said, whose mother, Billie Diaz, had two daughters with late husbandEmilio.

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"But then my career wasstarting to take off and there were still so many things I wanted to do," Cameroncontinued. "So that dream [of motherhood] for me was shattered early on.After that I never put another time line on anything in my life."

Jennifer became a first-time motherback in February 2008 at the age of 38 with former husband Marc Anthony andexplained that she experienced something many mothers do after giving birth – “babyblues!”

"I remember after the babieswere born, about seven to 10 days in, I was like, 'What is going on with me?' Ifelt sad and depressed and thought the babies didn't love me," Lopezconfessed to Redbook. "I actually remember picking up the book [What toExpect When You're Expecting] to try to see what was happening to me, andit said how you have this huge hormonal drop about seven to 10 days after yougive birth. It's called the 'baby blues.' But I just thought they didn't likeme!"

The film, which centers on fivedifferent couples and their journey through the precious nine months ofpregnancy, also stars Chace Crawford, Matthew Morrison, Dennis Quaid, ChrisRock and more! You can catch this hilarious flick when it hits theaters on May18^th!

Whose storyline in the film are YOU most excited to see? Let us know in the comments section below!

Photo Courtesy of Redbook & Getty Images