Nobhead, lots and lots of women bleed at all stages in their pregnancy and they and their babies are just fine, there'll be people along shortly with their positive stories for you :) so basically, please don't automatically assume the worst until you've actually been told to prepare for the worst as you'll drive yourself potty.
having said all that...
What they have said to you is standard practise as ultimately as the others have said there's nothing that can be done, and unless you are in severe pain, passing out/dizzy/weak or passing what you think is far too much blood, far too quickly then they won't really be wanting to see you I'm afraid. (and if those do happen, get onto NHS24/direct OOH GP or straight to A&E ok)
Now, assuming the worst, the best thing you can do is to prepare just in case as awful as it sounds, and I don't mean to upset you - have you got some strong painkillers (ibuprofen and paracetamol can be taken at the same time, co-codamol is good) a hot water bottle, some pads, old clothes/leggings or trackies are good, someone you can phone for support or to come and be with you asap if anything really starts? if you get to the point where it's inevitable then there is an excellent thread on the miscarriage board about how to cope with practialities, i will go and find it and bump it up just now...
and then just go and put your feet up if you possibly can and just relax as best you can.
Really hoping you'll be fine and if you get into the EPU tomorrow morning that everything will be found to be just as it should be x keep posting too, it really helps