Here is my 2 cents worth,

Like Fresia, see if your doc will order so more labs. Are you by any chance diabetic? I've not heard that diabetics have a bad smell but may have a sweet smell????? Maybe that isn't correct, but so many things can contribte to that.

Just being dehydrated can cause 'concentrated urine', which does have a strong odor, is a darker yellow and easy to fix by drinking more water, not Mountain Dew. Caffiene can cause dehydration too, making you have to go more often. When I get a little dehydrated, my first bathroom use in the morning is the strongest smelling.

Good thing you are having it checked out.