Is Hormone Fluctuation Causing Delay In Menses?

Doctor,

i hav missed my period..its now 43 days... i usually get my period between 28-35 days..conducted a pregnancy test at home but it is negative.... Can i be still pregnant.... i am having mensus like pain also...i fear whether i hav PCOD... when i had severe acne problem i had consulted dermatologist and he said there is slight hormone fluctuation and thats why periods are irregular..Gave me DIANE 35 medicine..asked me to hav it for 6 months..i had it for 6 months and stoppeit 5 months back...Doctor can i be pregnant even if the urine test is negative..if i hav PCOD...is it curable and can a person become pregnant if she has PCOD