Today is 30th day of my cycle Usually my period came on around 26-28 days of cycle This time it's of 30th days till I did not got my period Today morning having some dull pain in middle of lower back (rid bone) and it hurts when I touch my rid bone in lower side in middle Also there is no scene like pregnancy . What can be the reason then Having genital warts and previous episode of pid before 2 years.