What Causes Delay In Periods?

31 years of age. Diagnosed with PCOS, cycles have been regular(30 day cycles) for a year after about a year and a half of irregularities(between 30-50 day cycles) Currently taking zoloft 50mg daily, hctz(maxide?), and xanax as needed(once or twice a week) Period is 2 full weeks late based on my cycles for the last year but hpt are negative. Should I chalk this up to the PCOS again, or could it possibly be the diuretic causing insufficent hcg in my urine for the hpt to register? Not using any form of birth control and haven t since 2011