i’ve got constipation, i’m also on the pill, can i take senna tablets?

i’ve been on the pill for about half a year now. the pill i’m on is called celeste. recently, i’ve been suffering with constipation. i find it very difficult to pass stool! it really hurts and my bottom bleeds! i have a very poor diet. i don’t eat much high in fibre and i know this is a contributer to constipation! my mum bought me some senna tablets, which are classed as a herbal remedy for tradional use for the relief of occasion constipation! i haven’t taken them yet as i wanted to know if they will effect the pill, as i don’t want to get pregnant. will they be ok to use. help?