However, not all leaks are noticeable. You may have a small leak where the gas dissipates before you can smell it. The good news is that most gas suppliers offer a free yearly check. So call up your gas provider and ask them to send someone your way.
Also, make sure that the areas in your home that use gas – kitchen, heaters – are well ventilated. While natural gas is relatively clean, one byproduct is carbon monoxide. If you do not ventilate properly, your oxygen supply will be depleted.