24Weeks ++ No GTT tests yet.

Every time I go to see my OBGYN since 16 weeks , I have only been asked to give my urine sample for testing against Sugar & Protein & the results have always been No sugar No protein . But so far no GTT has been done . Is the urine sugar enough to indicate the presence of GDM like a precursor or so / will a GTT be done only later than 24weeks . What's the norm ?

I have had PCOD for 17yrs & had a hard time conceiving hence I am scared of GDM now for which PCOD is a probable cause. Should I be worried ?