What Causes Delayed Period And Abdominal Pain While HPT Is Negative?

Missed period Negative HPTs Lower abdominal pain?
It has been almost 35 days since the start of last menstrual period. Have taken two HPTs couple of days before and shows negative. But got pain in abdomen for some days till now.. May be had hard sex few days back affecting some organs as he is long? I some time before had irregular periods. Do i have PCOS or any cyst?? i also sometime faint during ovulation and periods and sometimes my period is heavy and long. Please advice...