<p>you have no reason to worry at all…relaaaaaaaaaax! Even a C here and there will not hurt you, a D? Maybe that would be reason for concern.
Remember they accepted you based on what you have done for the last 4 years and hate to rescind admission acceptances; they are not going to take it away for a B or a C in the last two months of your four month journey. It rarely happens and happens more for behavioral reasons that academic ones.</p>