My results are on a knife edge, its killing me! (Nottingham - Politics + IR)

I achieved BBB in AS. I got a conditional offer from Nottingham for Politics and international relations, this was ABB. However, I should point out that the standard offer for the course is AAB, under the "wider context" of my life the offer was reduced by the 1 grade.
My results could easily vary from BBC to ABB, but with BBB being the most likely results followed by ABB. I finshed my exams on Monday, since then my head is being go round like crazy and every free moment i have i will pull up the calculator and throw different variations of UMS marks in there.
I've checked around and looked at the consensus about missing grades it seems that one and sometimes two is acceptable for larger courses. But my concern is that my offer is already below the standard offer, does that mean I'm very unlikly to get in with BBB? or do they view it as "Hes missed HIS offer by 1?" etc. Please give me your views

Nott's often goes in clearing for courses and politics + IR is in UCAS Extra so the course isnt full which works in your favour.