Yes you needed to repeat the worming in 10-15 days to be effective. Take a look at my BYC page, I am in the middle of putting some info in about worming and dosing, etc. You might want to start over now. Your hens are what we would refer to as high risk because they came from several different sources. Not that you cant do that, its how many of us started out....just that it takes a bit more work sometimes to make sure one has not brought something to the others.
And the above poster is correct about animals stealing eggs. Snakes, raccoon's, opossums, and large rats are very eager to get their little paws on those eggs. So def. check the security of the coop.