What Causes Delayed Menstruation And Difficulty In Conceiving?

Hi ,I am 27 yrs old ..I am married.We are trying from a baby from 1 year.Initial test regarding my general health were fine (except urination infection which was treated in 14 days course)...From past 4 months my menses are getting delayed by 7 days to 11 days every month and still no chance of pregnancy ..any suggestion