I haven''t had a poo since delivery, is there something wrong?

No, this is very normal. The idea of pushing anything, where you are bruised or have stitches, appeals to no-one. Add to this the fact that you did not eat much the day of labour and possibly not much since so this will affect it too. Drink lots of water, increase the fibre in your diet and if necessary you could try gentle laxatives such as lactulose syrup.