Hi all.. Im now 4 days late for AF due on Sunday 17th... I have no signs of pregnancy an no signs of my AF arriving .. Usually suffer from really tender breasts running up to my AF (usually 4-5) days before and constant backache that worsens right up untill my AF arrives.. My boobs have been fine i had a smear of brown discharge in my underwear yesterday morning and nothing since ..( sorry if tmi) 
i have also suffered from cramps in my back but they keep coming and going and are no were near as bad as my usual AF back pains... I took a clearblue test monday NEG result ... I have done a repeat test also today also negative!! Wondering whether anyone else has had this problem but had successfully concieved or whether i may just be really late (usually always ontime regular 30 day cycle) any advice on anyones previous experiences with pregnancies.. With baby number #1 i cant remember any symptoms or signs so abit confused... Thanks ?