Cats can't walk up to you and say "hey, I'm not feeling so well", so oftentimes their way of letting you know something is wrong is by inappropriate behavior -- most commonly presented as inappropriate urination.

Fleas can take awhile to get rid of. If you're having problems, chances are that they are in your household. Flea pupae can lie dormant for MONTHS before hatching. We recommend that clients use a flea preventative for at LEAST 3 consecutive months on ALL PETS in the household (even indoor kitties) along with vigorous household vacuuming, laundry, etc, on a nearly daily basis to get rid of the flea population in the house hold. Noteworthy is that you may still see a tick or flea on your pet with frontline... it does not mean the product isn't working, but the flea/tick must bite the pet in order to die.

In any case... I strongly recommend a vet visit pronto. Cats are so good at hiding illnesses, that by the time you're seeing clinical signs, it can be bad (or it could be nothing... but nobody knows this over the internet, so to the vet you go!).