Katy Perry's childhood was ''just the Jesus train''.

The 'Teenage Dream' singer - who is expecting her first child with fiance Orlando Bloom - was raised by Christian pastors who ran a ministry from their home and she feels her upbringing centred only around ''pure bible thumping'', with no time for curiosity.

She said: ''My childhood was just the Jesus train. It wasn't expansive and it wasn't curious, it was just Sunday morning, Sunday night, Wednesday evening; Jesusjesusjesusjesusjesusjesusjesus.

''From birth, it was pure bible thumping..''

While Katy has been open about undergoing therapy, she admitted it was considered taboo in her household and people didn't express their feelings.

She told The Guardian newspaper: '' 'But Jesus cures all! By his stripes, you are healed! I'm sorry if your fingers are falling off but God will heal it.'

''It's like, if you don't have real intense true faith, then you're not the best Christian.

''But there's lots of tools that God gives us to be able to help ourselves, and science and doctors and therapists are some of them.

''That's probably why I'm in the business of feelings.''

The 35-year-old pop star first discovered how transformative her musical abilities were when she was just nine years old.

She recalled: ''Everyone went from ignoring me to whoosh, like now I had this magic trick of being able to hold attention.''

While the 'Chained to the Rhythm' hitmaker is keen to raise her children differently to how she was brought up, she doesn't think that's unusual.

She said: ''I think everybody wants to evolve from that.

''I think that's some of the reason why we do have children, to show that we have evolved. Or that we can.''