I know well what you mean by weird smell.   It is not permanent, but comes literally by waves (from time to time) !
I think it could be the amount of insulin produced by your body when your blood sugar is 3.4 for example.
At times I have been thinking that something was rotten !  I guessed it came from the kidney.  I found a way to cure it as follows :
3 teaspoonful of cocoa (I use Nestle)  with 2 teaspoonful of sugar in a glass of very warm tea.  I drank it twice or thrice daily.  That weird smell disappeared after a few days.
I am not a Doctor.  No Doctor has been able to tell me what was that weird smell as a residue from the urine.  The light pain from my right kidney also disappeared.
I do not know the real source of that weird smell !  if you learn something, please keep us posted.  Thanks.
I still drink my cocoa as mentioned above.  Feeling also more energy instead of being weak and sleepy with low blood sugar !