Some homeowners wait for leak to stop on its own. Never had that happen to me but seasonal leaks are possible especially only in winter.
Best thing to start with is, poking a hole on the drywall if possible with a pencil or something in similar diameter to contain the water in one spot. Place towels and place bucket to catch all the water while you contact your dependable contractor.
Once we are in communications and on location, in most cases same day. We can inspect the roof depending on the season we are in. During spring and summer it is visible to locate entry point but in winter, Ice damming is always the reason for leaks.
If it leaked last winter, there is a good possibility it may leak this year. Give us a call for all your Preventive Maintenance Services