Get Raid Flea killer off of Amazon. I had this problem when I moved into a new apartment in March. This stuff works great in combination of vacuuming daily and getting your cat or dog on Advantage flea medicine.
https://smile.amazon.com/gp/product/B00J5ISLNQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1