Beyonce used to fight with her father while he managed her.

The 31-year-old singer cut off her professional relationship with dad Mathew Knowles - who quit his job as a medical equipment salesman to help guide his daughter's career and helped form her group Destiny's Child in 1990 - in 2011 and now she has admitted he went into ''shock'' when she began to speak up for herself.

Speaking about the situation on 'Oprah's Next Chapter', Beyonce recalled: ''It took a while for me and my dad to have an understanding. When I turned 18 and started handling my business more, he went into shock.

''And we had our issues. I'd say 'No' to something, and he'd book it anyway.

''Then I'd have to do it because I'd look bad [if I didn't]. We would fight sometimes, and it took about two years, to when I was 20, for him to realise, 'Oh, she is an adult now, and if she doesn't wanna do something, I can't make her do it.' ''

Beyonce - who has 13-month-old daughter Blue Ivy with husband Jay-Z - also talked about her new HBO documentary 'Life Is But A Dream', which follows her pregnancy and other intimate moments behind the scenes, including her secret miscarriage, which was first revealed in her husband's song 'Glory'.

She continued: ''[The documentary] was the saddest thing I've ever been through. My life is a journey ... I had to go through my miscarriage, I believe I had to go through owning my company and managing myself.

''Ultimately your independence comes from knowing who you are and you being happy with yourself.''