A small leak in a roof can sometimes be difficult to locate. In some cases, water spots are visible some distance from the leak.
If there is a plastic barrier (vapor) between the insulation in your attic and the drywall, it is recommended to push the installation to the side and look for water stains on the plastic. In most cases rain water will travel to a ceiling light fixture.
On the other hand, if you cannot see any signs of water flow you may want to look for shiners at the underside of your roof. If a carpenter missed the framing member it will result in a “shiner.” On a cold night you will see moisture on the nails inside your attic.
A quick solution is to just clip the nail.