Carlos...It may be a slow leak. My husband goes up on the roof with a garden hose and hopes to find it with someone inside the house at the spot. As he said, however, if it is a slow leak they can be difficult to find. If you can find shingles that are torn/broken that might be a really good clue. Good luck!
Here's an article that might help you - https://www.todayshomeowner.com/video/tips-for-locating-hard-to-find-roof-leaks/
If you can get into the attic, look for damp areas to see where the leak is. If you are in a cold area and the attic is full of condensation then you require more air circulation to get rid of the frost. If you have any vents from your stove or toilet going into the attic they should be changed to go directly outside.
You might consider bringing in a pro for this as water leaks can come from an entirely different spot than where they show up. They're hard to track.