Sour Cream?!
Answers: How can you tell when sour cream has gone bad?
From the food reference I got they say you should be able to keep it a week after expiration but as soon as the litle green things grow on top you should throw it away immediately! I hope you didn't scrape and eat.
Sour cream is fine to eat as long as it hasn’t grown anything -- like blue or green mold. Even in that case, people have been known, when desperate for sour cream, to spoon off the surface mold and use what is underneath. This is not strictly recommended because not all molds are harmless and many will send roots deep into a food without the roots being detectable.