I'd say if you don't know you're water parameters then check them, but like fishluvr says, as long as you do normal routine water changes. No real worries!
I feel that once you establish a regular routine... and that routine works... then you have no real reason to constantly test to make sure it's still working...
My test kit likes to collect dust on the top. Unless you see a sudden change with your water quality, or with your fish, There's really no need to. Always a good thing to have just incase though.