Been there, done that! Never want deal with fleas again.
You may have to treat your yard, the favorite places your pets hang out.
I would use Capstar, bath and Frontline my girls, wash EVERYTHING washable in the house, spray everything sprayable, vacuum vacuum vacuum, and just when I would be confident and sit down relax, I would let Cassie and Reba out to the back yard, and then check them the minute they came in again with a flea comb. Sure enough they would have have a few more. It was freakin' endless.
Now we have the lawn treated for pests (fire ants, cinch bugs, etc.) so we just added flea and tick to the service and Trifexis replace Frontline for the dogs. This worked fairly quickly, I don't remember how quickly because you don't notice when you don't have fleas, only when you do!
Good luck