What happens if I don’t get the grades for uni?

Hi I’m 18F just about to take my a-level exams. My predicted grades are AAA and in recent mocks I have got A*AA.I have firmed Queens Mary university in London for LLB law and my insurance choice is Essex university for LLB law too.

Both universities have given me contextual offers (QMUL AAA & Essex CCC). I am more confident in my insurance choice, obviously because it’s lower grades and less pressure. I really want to get into QMUL as it’ll be better for a full law career.

(I did apply to UCL, Oxford due to interviews and LNAT scores and Nottingham, unfortunately got rejected from UCL and Oxford and then Nottingham changed my course.)

As exams are only a week away, I am starting to get nervous on if I don’t meet the AAA that QMUL wants. I did go to an open day and which they explained they would only lower the requirements on special cases. I’m not too sure if I would be a special case as I don’t live at home and I play professional sports.

If anyone that goes to QUML knows if I have to hit exactly that AAA, or if I didn’t hit those grades and go into cleaning, does any Russell groups like UCL,KCL,LSE do clearing for law or course that would lead me into the law field.