A leak in a roof is not necessarily an indication of a roof that needs replacing, but it is not a good sign. A roof leak will only worsen if not addressed. As a first point of action for a small leak in the roof, you don’t need to completely your roof, but you certainly do need to call a roofing contractor to stop the issue in its tracks and ensure that it won’t become a larger issue in the future.
A roofing contractor may be able to stop the leak in your roof and prevent further damage, then survey the issue and make a recommendation from there. You may find that the leak cannot be repaired by the roofing contractor, and it is at this point you need to replace the roof completely. Nevertheless, it is always best to call a professional before becoming too worried!