Huh? What kind of weird test kit has 7.0 as the highest end of the chart? Don't waste your money on buying a standalone liquid pH test kit. They usually run about $10 or more in pet stores. You're *much* better off getting a complete liquid test kit. The API Freshwater Master Test Kit comes with tests for pH, high range pH, ammonia, nitrite and nitrate and can be purchased at online stores like Drs. Foster and Smith and Aquariumguys for around $15. It will also last you a heck of a lot longer than strips will, as well as give you much more accurate readings.
In the meantime, you can take a sample of your water to a good fish store and have them test the water with a good test kit. Like others have pointed out, unless your pH is above 8.0 or something, there's really nothing to worry about. Also, like others have indicated, avoid pH-adjusting chemicals like the plague as they can cause huge pH swings.