Thats okay, just bear in mind that they may not always be accurate.
Will your LFS test your water?
If they do, you could continue using the test strips and if anything alarming appears (high ammonia, nitrite or nitrate), then you can take a sample of your water, do a 75% water change (more or less depending on how bad it looks) and then take the water sample to your LFS for testing and see how what the results are (make sure to ask for the exact results, don't accept "its fine") and then figure out what to do after that.