Just my opinion.......but I would definitely ask your vet. It all depends on the flea medicine and the puppies weight. Remy is 2 lbs 3 ounces and I have not used any flea medicine yet. My vet gave me a Comfortis pill to give him once he reached 2 lbs. Knowing my Remy he will not eat that big pill. I have the Revolution/Stronghold puppy medicine that I am going to use on him soon. Each puppy is different but my concern would be that your medicine says 3 to 9 lbs and your baby is only 2 lbs.
I hope this helps.
__________________ Catherine-Mommy to  Remy  1 yr 9mths Roxy  6 years  RIP Fritz & Hershey 7/2011 My little dog — a heartbeat at my feet. ~Edith Wharton |