GCSE grade nerves

Hi!

I'm just about to sit the Physics IGCSE tomorrow and it suddenly dawned on me that my grades may not be as good as I wanted. I ideally wanted about 8 A*s but now I think I'm on the boundary for so many subjects and am worrying if I've achieved the A*.

In Maths, I think I got about 69/100 in the first paper but 83/100 in the second but would this be enough to get me an A* in IGCSE Edexcel?

And for Chemistry, I think I got around 90/120 in paper 1 and 44/60 in Paper 2 but once again would that be enough for the A*?

Physics looks like it will go terribly and for someone who wants to go to a top university (hopefully in America), are 7 A*'s, 2 A's and a B good enough?

Thanks,
Edward