OK, I'm studying Law at Nottingham.
I got ABBB at AS Level (the three Bs were a matter of a few UMS away from As) and was predicted AAA at A2. I got 25 on the LNAT.
Nottingham offered me a place as long as I secured A*AA.
Three of my teachers fell ill during my A2 year for an extended period of time and I found myself without teachers. Long story short, I ended up with ABB at A2. Nottingham still allowed me in.
This gives you hope, I would try to push at least one of those Bs up to an A, though, to ensure an offer.
I wouldn't want you to become fixated on the idea that Nottingham will drop their grades for you, though. I was very lucky, and I'm still not sure why they did it. They will look at an array of information when deciding to offer you a place, and then subsequently whether to take you if you do not achieve their grades in August. They will take in to account your personal statement, reference, predictions, extra curricular activities and perhaps most importantly, the LNAT test.
I have a friend who achieved AAAA at AS Level and was predicted A*A*A at A2. She applied to three different LNAT universities (including Nottingham), but only achieved 17. She was declined from all three, and now studies at Exeter (still a great university!)
As I said, this gives you some hope, but do work hard to try and get at least one A at AS. Also, most people at Nottingham got AAA or higher, so it's not often they drop as low as they did for me. I was extremely lucky.