my odometer has stopped working

Bizarre. Yes, you should be worried. I'm not sure how you'll handle that issue if you decide to re-sell the car. Do you have any sense of the true number of miles you've got on the car?

u should check on the cable wire reaching to the gauges!

That is one of the things prone to failure in that generation Pathfinder. The odo stopped turning over on my 95, and to the mechanic it went. He had to go inside and replace a gear, or something like that. It was several years ago, so I don't remember exactly. By my driving habits, I know that I went about a thousand miles before the fix, so I adjusted the maintenance accordingly. Check your frame for rust, another common problem. That's why I had to get rid of my 95.