Jessica Biel was ''surprised'' by how long it took her to get pregnant.

The 'Total Recall' star welcomed son Silas Randall - who she shares with husband Justin Timberlake - into the world two years ago but admits her journey towards her pregnancy wasn't as smooth sailing as she thought.

Speaking on Good Morning America, she said: ''We all know how to have a family, but it's not as easy as we think it is anymore. Sometimes it takes a long time to become pregnant, and that's what I was surprised about with myself and my own knowledge or misinformation about my own body.''

Meanwhile, Jessica previously confessed she is Justin ''number one fangirl''.

She wrote on Instagram: ''A picture says a thousand words. And thank goodness because there aren't enough to express ALL the aspects of my love and respect for you. Here's to a spectacular year ahead. I'm so proud of all you've accomplished and all that is ahead for you. plus you're a super hot dad. A ninja dad. A kiddie teeth brushing, Jedi sleep mind tricking, intimidating dad voice disciplining SUPER HOT DAD. I love you, you hot dad.. I'm here, right by your side, OG fan girl #1. Happy birthday, my beloved. Now go crush it this weekend at SB LII. (sic)''

And the 35-year-old actress previously revealed her and Justin's relationship works because they're both ''selfish''.

Opening up about their ''similarities'', she added: ''We really have a lot of similarities. We believe in loyalty, honesty. We like to have fun. Also, in the business, we're very career-oriented, and you have to be a little selfish. I understand that about my peers - about being focused and driven - and if you have someone who shares the same values as you, it's like, 'Score!'''