The Duchess of Cambridge has described motherhood as a "rewarding" yet "overwhelming".
The 35-year-old royal, who has three-year-old son Prince George and 22-month-old daughter Princess Charlotte with her husband the Duke of Cambridge - has admitted it is a "wonderful experience" being a parent, but it is also a "huge challenge" at times, although she is lucky to have support on hand to help her cope.
Speaking about motherhood at the launch of Heads Together charity partner Best Beginnings' 'Out of the Blue' film series, which helps to raise awareness to mental health among women and children, she said: "I would like to thank Best Beginnings for inviting me here, to introduce the 'Out of the Blue' series. This collection of films shows how important it is to be open about mental health especially in the early years of parenthood.
"Personally, becoming a mother has been such a rewarding and wonderful experience. However, at times, it's also been a huge challenge.
Even for me, who has support at home that most mothers do not, nothing could really prepare you for the sheer overwhelming experience of what it means to become a mother."
And the brunette beauty - who was known as Kate Middleton before marrying the 34-year-old royal - has revealed she was left feeling a mixture of "complex emotions" when she realised she doesn't have to think of just herself but her brood too.
She continued: "It is full of complex emotions of joy, exhaustion, love and worry all mixed together. Your fundamental identity changes over night. You go from thinking of yourself of primarily an individual to suddenly being a mother first and foremost. Yet, there is no rule book, no right or wrong. You just have to make I up and do the very best you can to care for your family.
"For many mother, myself included, this can, at times, lead to a lack of confidence.
"Some of this fear is the pressure to be a perfect parent.
"It is right to talk about motherhood as a wonderful thing, but we also need to talk about the stresses and strains. It's okay not to find it easy, and asking for help should not be seen as a sign of weakness."