Usually the film is not ruined. On many manual-wind 35mm cameras, once the film reaches the end, the advance gets noticeably tight and either stops moving film or slips via a clutch designed to prevent damage. In that case, the shutter often won’t keep operating normally unless the film actually advances, so you may simply have gotten a few extra frames if the roll had a little more length than advertised.

Possible outcomes are:

• you got lucky and the roll allowed a few extra exposures,
• the camera’s advance slipped harmlessly once the roll was finished,
• or, less ideally, the film stopped moving and you made multiple exposures on the last frame.

If rewinding felt normal, that’s a good sign the film likely wasn’t torn or badly damaged. Serious damage would usually involve torn sprocket holes or a jam. So the most likely result is either a few bonus frames or some overlap near the end, not a completely ruined roll.