I think it might depend on the hospital, or maybe your age, i've known people just to go, get stitched up and be able to leave straight away, yet when I went I was made to stay while 2 psycs came and talked to me It was all a bit of a blur so I don't really remember what the difference between them was, sorry but one gave me loads of leaflets and a crisis card and some other stuff and the other spent about 45 minutes talking to me about what made me hurt myself and my home life and school e.t.c.
if you follow this link
http://www.recoveryourlife.com/index.php?categoryid=180 there are 5 articles about what to expect in A&E and notes on hospital treatment e.t.c and the one i found most useful, reasons you might need to go to A&E (last article). But i would say if you are unsure go to the hospital anyway, just incase.