it's impossible to tell you now what the situation will be next summer. its possible you could go through clearing but it may be that of the unis who offer less than BBB, all the ones that you would like to go to dont need to offer places through clearing and so you end up somewhere you don't want to go.
clearing is a very stressful process- theres lots of students chasing places at the remaining unis, you have little time to look at the different unis and you often have to make a decision very fast.
it's not the end of the world-one of my friends went through clearing and is very happy at her current uni but i wouldn't advise relying on clearing like that.