Yes, please do be careful not to overtreat. Which pill is it? Comfortis is the monthly one, and Capstar is the one that can be given more frequently, though it does not continue to protect like the Comfortis. Flea Allergy is horrible, my girls continue to scratch for days and even weeks after exposure to even one flea
They both had to get an anti-inflammatory shot from the vet, and Luna had even developed a secondary skin infection from scratching so much
Yes, you will have to be aggressive with the fleas. Lots of vacuuming and proper disposal of the bag or contents of the cannister. Please Google "Flea Life Cycle", this will give you some of the timelines of what stages could be present in the home, and the best ways to eliminate them. Some treatments only kill the adult fleas, and if so, the eggs and larvae will survive and before you know it, you have adult fleas again. It is VERY frustrating, but you CAN and WILL win with persistence and vigilance.
Thinking of you!