Midyear grades?

I'm finally done sending in all my college apps, but i still have to send in my mid-year report, which has me worrying. I've applied to a lot of prestigious schools, such as UPenn, Harvard, and MIT. My academic history is pretty good. However, I've signed up for four AP cles my senior year, and most likely I will end up with B's in three of those cles and 1 A. I have two other non AP cles, that I will have A's in. Will this decrease my chances of being accepted by a lot? And what about if i only have 2 B's, instead of 3? Would that be a lot better, or just a little bit. Thanks!