If my house is infested with fleas why can't i find them on my cat?

I've tried the pan with soapy water and light source, i searched her for flea dirt and for fleas and i never can find any. but i found one on me. and i have a few bites so i guess that means my house is infested.. i am allergic to them and i have a newborn and i just dont know what to do anymore.. the sound of infested really upsets me .. i just cant stand the thought of my house over run with fleas. ive done everything.. shes on a flea treatment from the bet, ive shampooed and vacummed the entire house washed all the clothes .. i dont want to set bombs off because of my newborn. and the powder im putting on my carpet is strong. I just need a easy way to get rid of them.. the emotional stress of taking care of my newborn and worrying with a flea problem is driving me insane.. literally. i a really allergic so when they bite me i am miserable.. but i cant seem to prove they are in my house .. i tried white socks on the carpet.. white blankets.. my cat actually has really clean skin. i cant find a flea on her… im so confused. I just need a solution that will work.. no bs.