birthday cards

I am so grateful to my lovely friends for their birthday kindness and generosity. I have lots of lovely cards and presents and because my Mum was so generous I think I am going to be able to finally, after nearly a year of saving up, buy a macbook (they didn’t have any in at John Lewis when I went at the weekend – JL offer a 2 year guarantee so are my choice of supplier). So, I really am a very fortunate birthday girl. Except it isn’t my birthday anymore…and I would like some advice on how long to keep my cards up. I think a week is about right but I am already thinking they need to come down. What do you think? What is official card etiquette?