Don't worry about it! Honestly, 90% of people I know got small dogs at 8 weeks and under and they are perfectly fine healthy socialized dogs.
I think for every dog that has issues that was taken from its mother at 8 weeks, you will have just as many with issues taken 12 weeks and later. Most dogs go to new homes at 8 weeks old and most do perfectly fine with it.
I got Jackson at 9 weeks old and wouldn't have wanted him to stay there any longer anyway! He's a great dog, never had any issues as a pup either.