What Causes Delayed Period And Negative UPT While Having PCOS?

Hi, I am 32 yrs old and have been married for 2 years and trying to start a family for 7-8months now. I have had PCOD even before my wedding. My period as are mostly irregular. I have been taking home pregnancy test on 40th day and 45th day of my cycle and when it shows negative I start deviry 10mg 3 times for 5 days as has been advices by my doctor. Also I have been taking fertomide on the 3rd day of my periods. This has been happening for abt 7 months and I usually get my periods within 10days of starting the course of deviry. This time.. It has been 12 days n yet there are no signs of periods. Not even spotting. Could I be pregnant? But I did take a home test on my 40th day n 43rd day of cycle. My husban n I have gone through most of the basic tests and everything is normal. Yet we are having trouble conceiving. Could I be pregnant despite deviry?? Or am I panicking for no reason n should wait for my periods a lil longer? Or is there something else to it entirely? Please advice