He wormed them at the office and gave you another dose to give them so many days later?

I will leave the answers to your questions to the experts with more experience here but I do know if you don't get rid of the fleas, they will get the worms back and with mine, even treating them, they kept getting them so I had to change the kind of flea treatment was I using and haven't had a problem since.

Good for you, getting them to a vet!